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Research involving Lowell Observatory staff 2022
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This is a work ever in progress.

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Years: 2022 Bottom


  1. Hofgartner, J., Birch, S., Castillo, J., et al., (including Grundy, W.), 2022, AGUFM, 2022, P23B-03, Hypotheses for Triton's Plumes: New Analyses and Future Remote Sensing Tests
    At least two active plumes were observed on Neptune's moon Triton during the Voyager 2 flyby in 1989. An eruption model based on a solar-powered, solid-state greenhouse effect was previously considered the leading hypothesis for Triton's plumes, in part due to the plumes' proximity to the subsolar latitude during the Voyager 2 flyby and the distribution of Triton's fans, which are putatively deposits from former plumes. Two other eruption hypotheses, cryovolcanism and a model based on basal heating of an insulating volatile-ice sheet, are powered by internal heat, not solar insolation. Based on new analyses of the ostensible relation between the latitude of the subsolar point on Triton and the geographic locations of the plumes and fans, we argue that neither the locations of the plumes nor fans are strong evidence in favor of the solar-powered hypothesis. We conclude that all three eruption hypotheses should be considered further, and that new hypotheses should be pursued. Five tests are presented that could be implemented with remote sensing observations from future spacecraft to confidently distinguish among the eruption hypotheses for Triton's plumes. The five tests are based on the: (1) composition and thickness of Triton's southern hemisphere terrains, (2) composition of fan deposits, (3) distribution of active plumes, (4) distribution of fans, and (5) surface temperature at the locations of plumes and/or fans. The tests are independent, but complementary, and could be implemented with a single flyby spacecraft mission.
  2. Johnson, J., Grundy, W., Lemmon, M., et al., 2022, AGUFM, 2022, P25F-2169, Spectrophotometric Properties of Materials from the Mars Science Laboratory at Gale Crater: Bradbury Landing to Cooperstown
    During the first 443 martian days (sols) of the Mars Science Laboratory (MSL) Curiosity rover mission, visible/near-infrared (445-1012 nm) multispectral observations were acquired at different times of sol by the Mast Camera (Mastcam) and Navigation Camera (Navcam) at five locations along the traverse. Measurements of soil, dust, and rock units spanned sufficient incidence, emission, and phase angles to enable radiative transfer models to constrain the surface scattering functions, single-scattering albedo (w), and microphysical properties of the units at each site. Although the model results were mainly consistent with previous results from other landing sites, there were some notable exceptions. For example, the less dusty "Blue rocks" units were modeled as more backscattering compared to ostensibly dustier "Red rocks" units, which was opposite to results from other landed missions. Relations between the peak phase angle of phase curve ratios, w values, and macroscopic roughness () suggested that unlike most of the materials observed by the Spirit and Opportunity rovers, the effects of particle-scale roughness and internal scattering were a greater influence on MSL units than surface scattering. Also noteworthy were unique photometric signatures modeled from data acquired at the landing site on Sol 20 as part of the first in situ spectrophotometric analyses of materials subjected to erosion and/or surface dust removal from spacecraft descent engines. Modeled w spectra were relatively flat and dark for the Sol 20 Blue rocks unit and were positively correlated with average values, similar to some laboratory studies of coarse-grained and/or glassy mafic materials. While low w values and backscattering behaviors were modeled for the Sol 20 "Regolith" unit, the more heavily scoured, lighter-toned regions included soils with extremely forward scattering behaviors, large w values, and that lacked ferric absorption features. The absence of phase reddening effects in all the Sol 20 units likely also was caused by surface disruptions during the landing. Future analyses of additional spectrophotometric data sets from both Curiosity and the Mars 2020 Perseverance rover will continue to yield important comparisons among the variable scattering properties of martian geologic units.
  3. Lisse, C., Steckloff, J., Prialnik, D., et al., (including Kareta, T.), 2022, AGUFM, 2022, P26A-02, 29P/Schwassmann-Wachmann: A Rosetta Stone for Amorphous Water Ice and CO -> CO2 Conversion in Centaurs and Comets?
    Centaur 29P/Schwassmann-Wachmann 1 is a highly active object orbiting in the transitional "Gateway" region between the Centaur and Jupiter Family Comet regions. SW1 is unique among the Centaurs, in that it experiences quasi-regular major outbursts and produces CO emission continuously; however, the source of the CO is unclear. We argue that due to its very large size (~32 -14/+28 km radius), Centaur SW1 is likely still responding, via amorphous water ice (AWI) conversion to crystalline water ice (CWI), to the "sudden" change in its external thermal environment produced by its dynamical migration from the Kuiper belt to the Gateway Region at the inner edge of the Centaur region at 6 au. It is this conversion process that we believe is the source of the abundant CO and dust released from the object during its quiescent and outburst phases. If correct, these arguments have a number of important, testable predictions, including: the quick release on Myr timescales of CO from AWI conversion for any few km-scale scattered disk TNO transiting into the inner system; that to date SW1 has only converted between 50 to 65% of its nuclear AWI to CWI; that volume changes upon AWI conversion could have caused subsidence and cave-ins, but not significant mass wasting on SW1; that SW1's coma should contain abundant amounts of CWI CO2-rich "dust" particles; and that when SW1 transits into the inner system within the next ~1 Myr, it will be a very different kind of SP comet.
  4. Gustafsson, A., Protopapa, S., Grundy, W., et al., 2022, AGUFM, 2022, P26A-05, Spatial Distribution and Secular Evolution of Pluto's Ices as Seen from the Ground and Space
    An up-close, detailed snapshot of the complex cryogenic world of Pluto was revealed by NASA's New Horizons mission (Stern et al. 2015, Science 350). The striking surface heterogeneity of this large trans-Neptunian object is due in part to the seasonal transport of three volatile ices: nitrogen (N2), methane (CH4), and carbon monoxide (CO). In order to better understand the processes responsible for the sublimation and redistribution of these volatile ices on Pluto, a broad seasonal context is necessary. This can only be achieved through analysis of data monitoring Pluto over timescales of years.

    With the goal of deriving information on the role that each volatile ice plays in sculpting the variable surface composition of Pluto, we performed an analysis of IRTF/SpeX near-infrared data covering the timeframe from 2001 to 2021 (Grundy et al. 2013, Icarus 223; Grundy et al. 2014, Icarus 235) and New Horizons spectral maps acquired in 2015. Our analysis relies on the evaluation of spectral parameters, including band depth and equivalent width and spectral modeling adopting a modern radiative transfer code (Hapke 2012, Icarus 221; Protopapa et al. 2017, Icarus 287). We interpret the varying spectral profile of Pluto in terms of variations in mixing ratio and/or path length of Pluto's volatile ices. Overall, these results (1) enable us to interpret the temporal evolution and spatial distribution of N2, CH4, and CO over two decades and (2) permit a direct linkage between spectral features in disk integrated spectra acquired in 2015 and geological units revealed by New Horizons compositional maps (e.g., Protopapa et al. 2017, Icarus 287; Gabasova et al. 2021, Icarus 356).

    This work was funded by the NASA Solar System Workings and New Frontiers Data Analysis Program via contracts 80NSSC19K0554 and 80NSSC19K0821 to SwRI (PI: Protopapa).

  5. Jewell, A., Hennessy, J., Rodriguez, R., et al., (including Llama, J.), 2022, AGUFM, 2022, P36B-01, UV Detectors and Instrumentation for Exoplanet Studies
    The Star-Planet Activity Research CubeSat (SPARCS) mission is a dedicated 6U CubeSat mission aimed at characterizing the quiescent and flare behavior of low-mass (0.1 to 0.6 Msun) M-dwarf stars. Information learned through short- (hours) and long- (days) term observations in two ultraviolet (UV) bands will be key to interpreting planetary atmospheric composition data and discriminating the source of biosignatures observed by missions like the James Webb Space Telescope (JWST). In this presentation I will review the SPARCS instrument design with a focus on the enabling UV detector and instrument technologies. The SPARCS payload includes a 9-cm aperture telescope and advanced delta-doped UV detectors; a dichroic beam splitter will direct the incoming light to the two science detectors allowing for simultaneous and independent observations in the far and near UV (150-170 nm and 260-300 nm, respectively). Out of band light (i.e. red leak) suppression will be achieved with a stand-alone bandpass filter in the NUV and a device-integrated bandpass filter in the FUV; allowing for several orders of magnitude red leak suppression.
  6. Thomas, C., Moskovitz, N., Pravec, P., et al., 2022, AGUFM, 2022, P52A-02, Pre and Post-Impact Observations of Didymos in Support of NASA's DART Mission
    NASA's DART (Double Asteroid Redirection Test) will impact the secondary of the near-Earth binary asteroid (65803) Didymos on September 26, 2022 in the first test of a kinetic impact for planetary defense. The impact into Dimorphos, the system secondary, will change the binary orbit period by at least 73 seconds. The main requirement of the DART Observations Working Group is to measure and characterize the deflection caused by the impact. The initial orbit was defined following the discovery apparition in 2003 (Pravec et al. 2006). We obtained lightcurve photometry during apparitions in 2015, 2017, 2019, and 2020-2021 to study the pre-impact orbit and provide the location of Dimorphos at the time of the kinetic impact (Pravec et al. 2022, Scheirich & Pravec 2022, Naidu et al. in press).

    Our current observing window began in late June 2022 and will continue through March 2023. We will monitor the pre-impact orbit and then transition our observations to studying the post-impact orbital period. We will use ground and space-based telescopes as part of an extensive observing campaign to study the Didymos system in detail. Our observational efforts are divided into three categories: lightcurve photometry to measure the orbital period change, characterization observations to understand the physical properties of the target system, and observations of the ejecta during and after impact to study the evolution of the material. We are particularly focused on the lightcurve observations due to their importance to the DART mission. We will discuss our observational dataset, future plans, and some noteworthy results. The detailed modeling of the orbital period will be discussed by Naidu et al. and Scheirich et al. (abstracts submitted to this session).

  7. Naidu, S., Chesley, S., Benner, L., et al., (including Moskovitz, N.), 2022, AGUFM, 2022, P53B-01, Estimating the Change in the Mutual Orbit of Dimorphos Due to the DART Impact Using Lightcurve and Radar Observations
    Binary near-Earth asteroid 65803 Didymos is the target of NASA's Double Asteroid Redirection Test (DART) mission, a test of the kinetic impactor approach to planetary defense (Cheng et al., 2016). The spacecraft was launched in 2021 November and will impact Dimorphos, the satellite of Didymos, on 2022 September 26 at 23:14 UT. The primary objectives of the DART mission are to shorten the orbital period of Dimorphos, measure the change using ground-based observations, and estimate the momentum transfer efficiency of the impact. The DART impact is expected to reduce the orbital period of Dimorphos by at least 7 minutes (Cheng et al., 2016, Rivkin et al. 2021); the minimum change for mission success, a "level 1 requirement," is at least 73 seconds. Ground-based photometric observations of the system are planned between July 2022 to March 2023 and will yield lightcurves showing eclipses and occultations between the two components. Didymos will also be observed with monostatic and bistatic radar configurations using the Goldstone and Green Bank telescopes between September 27, about 11 hours after the DART impact, and October 22. We will use the times of the lightcurve mutual events and delay and Doppler measurements of Dimorphos relative to Didymos to estimate the mutual orbit parameters and the change in the orbit period due to the DART impact. We will discuss initial results at the conference.
  8. Weaver, H., Spencer, J., Marchi, S., et al., (including Moskovitz, N.), 2022, AGUFM, 2022, P54C-01, Investigating the DART Impact Event with the Lucy LOng Range Reconnaissance Imager
    NASA's Lucy mission is the first to provide flyby reconnaissance of the Jovian trojan asteroids, which are thought to be primordial small bodies that formed at a variety of heliocentric distances during the early stages of the solar system's formation and were subsequently captured into Jupiter's L4 and L5 Lagrange stability zones. Since its successful launch on 2021-Oct-16, the Lucy spacecraft has been orbiting the sun within the inner solar system. On 2022-Oct-16, Lucy executes the first of three Earth Gravity Assists (EGAs) that put the spacecraft on the correct trajectory to achieve its encounters with the Jovian trojans. The DART kinetic impact on the secondary body of the Didymos-Dimorphos binary system occurs 20 days prior to EGA1, at a time when the Lucy spacecraft is well-placed to observe it. Lucy carries a sensitive panchromatic camera, the Lucy LOng Range Reconnaissance Imager (L'LORRI), which is capable of detecting the binary system with high signal-to-noise ratio (SNR) and with temporal cadences as fast as once per second.

    The observing geometry from Lucy is similar to that from the Earth: the range to the Didymos system is 0.126 au from Lucy vs 0.0757 au from Earth, and the solar phase angle is 31.9 deg vs 53.2 deg. The L'LORRI investigation of the DART impact event is divided into eight separate observational phases, starting 12 hr before the impact and ending 24 hr afterwards. L'LORRI cannot resolve the binary, but instead records the total brightness, which is expected to increase after the DART impact due to reflected sunlight from the ejecta. The first two phases are designed to obtain baseline photometry of the Didymos system covering both the Didymos-Dimorphos mutual orbit period (11.92 hr) and the rotational period of Didymos (2.26 hr). Phase 3 covers the impact event itself at one second cadence, starting 3 minutes before impact and ending 4 minutes afterwards. Lucy has a clear view of the predicted DART impact site, theoretically enabling L'LORRI to detect an optical flash in the unlikely event it is brighter than Didymos itself. L'LORRI observations during phases 4 through 8 are designed to monitor the temporal and spatial evolution of ejecta associated with the impact event, but ejecta don't leave the central pixel during Lucy's observing period unless their speed is greater than about 2 m/s.

  9. Metcalfe, T., Finley, A., Kochukhov, O., et al., (including Clark, C.), 2022, csss, 72, Confirmation of a Magnetic Morphology Shift in Old Solar Analogs
    The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. The rate of angular momentum loss depends on the strength and morphology of the magnetic field, the mass-loss rate, and the stellar rotation period, mass, and radius. Previous observations revealed a shift in magnetic morphology between two F-type stars with comparable rotation rates but very different ages. We confirm a similar transition in several well-characterized solar analogs with ages between 2 and 7 Gyr. We present new spectropolarimetry of 18 Sco and 16 Cyg A & B from the Large Binocular Telescope, and we reanalyze previously published Zeeman Doppler images of HD 76151 and 18 Sco to confirm a shift in magnetic morphology near the middle of main-sequence lifetimes. We combine archival X-ray observations with updated distances from Gaia to estimate mass-loss rates, and we adopt precise stellar properties from asteroseismology and other sources. We then calculate the wind braking torque for each star in the evolutionary sequence, and we assess the uncertainties that arise from errors in the observational inputs. We conclude that the shift in magnetic morphology occurs before the age of the Sun, reinforcing the notion that the solar dynamo may be in a transitional evolutionary phase. We suggest that this magnetic transition may represent a disruption of the global dynamo arising from weaker differential rotation, and we outline our plans to probe this behavior in additional stars spanning a wide range of spectral types.
  10. Hamilton-Drager, C., Finder, H., Gimmy, K., et al., (including Skiff, B.), 2022, csss, 202, An Update on the Eclipsing Binary System V582 Mon (KH 15D): Nearing the End of an Era
    Almost twenty five years ago the variable star, V582 Mon, was re-discovered by Kearns and Herbst and henceforth has also been known as KH 15D. In this poster, I will review the history of this intriguing system, and what it represents: an opportunity to study a pre-main sequence (PMS) binary system still embedded in an accretion disk. The steady precession of the occulting circumbinary (CB) ring has allowed us to derive the stellar properties of both stars, and presents us with the opportunity to refine and expand current models of the system. The latest observations reveal significant structure in the trailing edge.
  11. Grouffal, S., Santerne, A., Bourrier, V., et al., (including Kunovac, V.), 2022, A&A, 668, A172, Rossiter-McLaughlin detection of the 9-month period transiting exoplanet HIP41378 d
    The Rossiter-McLaughlin (RM) effect is a method that allows us to measure the orbital obliquity of planets, which is an important constraint that has been used to understand the formation and migration mechanisms of planets, especially for hot Jupiters. In this paper, we present the RM observation of the Neptune-sized long-period transiting planet HIP41378 d. Those observations were obtained using the HARPS-N/TNG and ESPRESSO/ESO-VLT spectrographs over two transit events in 2019 and 2022. The analysis of the data with both the classical RM and the RM Revolutions methods allows us to confirm that the orbital period of this planet is ~278 days and that the planet is on a prograde orbit with an obliquity of = 57.117.9+26.1, a value which is consistent between both methods. HIP41378 d is the longest period planet for which the obliquity has been measured so far. We do not detect transit timing variations with a precision of 30 and 100 minutes for the 2019 and 2022 transits, respectively. This result also illustrates that the RM effect provides a solution to follow up on the transit of small and long-period planets such as those that will be detected by ESA's forthcoming PLATO mission.
  12. Urasaki, C., Meech, K., Keane, J., et al., (including Schleicher, D.), 2022, DPS, 54, 101.07, Activity of comet C/2014 S2 (PANSTARRS)
    We report on the activity of comet C/2014 S2 (PANSTARRS). We use photometric data from PanSTARRS, ATLAS, CFHT, DECam, and amateur data, beginning at a heliocentric distance r = 5.00 au through r = 8.13 au post-perihelion. We present a model of the activity that incorporates surface water-ice sublimation and sub-surface CO2 sublimation that matches the photometry and gas production rates. Using this model, we estimate the nucleus radius to be 3.2 km (upper limit 3.7 km) assuming an albedo of 0.04. From NEOWISE observations, we calculate production rates of QCO2 = (4.28 0.06) x 1027, (3.09 0.04) x 1027, (2.61 0.01) x 1027, and (6.10 0.08) x 1027 [s-1] at r = 2.43 au, 2.13 au pre-perihelion, and r = 2.14 au and 2.67 au, post-perihelion. Keck telescope NIRSPEC observations yield QH2O = (2.13 0.61) x 1028 s-1 at r = 2.17 au post-perihelion. We observe a dramatic increase in brightness at r ~ 2.56 au pre-perihelion likely from a delayed on-set of subsurface CO2 We observed three suspected CO2-driven outburst events, one pre-perihelion at r = 5.38 au, and two post-perihelion at r = 2.30 au and 5.08 au. To match the observed H2O production from Keck and Lowell observatories, we combined water sublimating from both the nucleus surface and from large (>50 m) ice grains ejected via CO2 sublimation. These large grains, having been lifted off the surface through smaller outbursts, enter the coma and can begin sublimating, contributing to higher than expected activity for a comet of this size (effective fractional active area of 36% for water). For various grain radii and albedos, we find that there is a sufficient number of grains produced by our models to make up the difference in sublimating area and that they, with the exception of those with very large radii (~200 m) and very high (~0.8) albedos, sublimate completely before crossing out of the observing aperture. We compute estimates for the energy per unit mass of ejecta and compare it with the specific energy of an amorphous to crystalline ice transition to compare to possible mechanisms for the outbursts
  13. Devogele, M., Masiero, J., Vega Santiago, N., et al., (including Moskovitz, N.), 2022, DPS, 54, 104.02, Polarimetry as a tool for physical characterization of potentially hazardous NEOs
    The degree of linear polarization of sunlight scattered by an asteroid contains valuable information for rapid characterization of the surface properties of Near-Earth objects (NEOs). In the case of atmosphereless bodies the state of linear polarization varies as a function of the phase angle () and is described using the so-called Pr parameter [1].

    The properties of the phase-polarization curve of an asteroid are mostly defined by its albedo (pV). Numerous calibrations between polarization and pV have been proposed for main-belt asteroids [2, 3]. However, main-belt asteroids rarely exceed phase angle > 30 while near Earth objects can be observed at phase angle as large as 100[4]. These observations at higher phase angles allow for deeper characterization of the observed object, but there is currently a lack of observations of NEOs in polarimetry to accurately calibrate the albedo-polarization relationship at high phase angles.

    We recently started a survey of Near-earth Objects in polarimetry to characterize their phase-polarization curve at high phase angle in order to calibrate the relation between polarization and albedo. These polarimetric observations are complemented with visible photometry, thermal infra-red, spectroscopy, and/or radar observations to obtain independent characterization of the size, shape, albedo, and other surface properties of the objects observed in polarimetry.

    In this presentation, we will present the polarimetric observations obtained so far. We describe the large variety variety of polarimetric response at high phase angle with polarization ranging from 1 to 50% when observed at the same phase angle. We also discuss the first results using physical characterization using radar, photometric, and thermal observations and how these can be used to calibrate the relation existing between polarimetry and albedo.

    [1] I. Belskaya, A. Cellino, R. Gil-Hutton, et al., Asteroid Polarimetry, Asteroid IV, (2015) 151-163

    [2] A. Cellino, R. Gil-Hutton, A. Dell'Oro, et al. A new calibration of the albedo-polarization relation for the asteroids, JQSRT 113 (2012) 25522560.

    [3] A. Cellino, S. Bagnulo, R. Gil-Hutton, et al., On the calibration of the relation between geometric albedo and polarimetric properties for the asteroids, MNRAS 451 (2015) 34733488.

    [4] M. Devogele, A. Cellino, G. Borisov, et al. The phase-polarization curve of asteroid (3200) Phaethon, MNRAS, 479 (2018) 3498-3508

  14. Bird, M., Linscott, I., Tyler, L., et al., (including Grundy, W.), 2022, DPS, 54, 105.01, Brightness Temperature of the Kuiper Belt Object Arrokoth at 4.2 cm: REX-Radiometry during the New Horizons Encounter
    The New Horizons Spacecraft encountered the Kuiper Belt Object (KBO) Arrokoth on the first day of 2019. The Radio Science Experiment (REX) on New Horizons performed radiometry measurements of the KBO's thermal emission at = 4.2 cm during approach on the dayside and also during departure on the nightside. Owing to the small size of the target, only a global estimate of the mean brightness temperature was possible. A brightness temperature Tb = 29 5 K was derived for the nightside observation, less than Arrokoth's predicted surface equilibrium temperature of ~50 K on the dayside. An estimate of Tb on the dayside was not possible due to unexpectedly large variations in the REX system temperature. A comprehensive model of KBO Arrokoth is used to constrain the global values of emissivity, thermal inertia and electrical skin depth of the KBO. In particular, models with small values of thermal inertia and small values of electrical skin depth can be excluded. High values of the effective radio emissivity (Eeff > 0.8) provide better agreement with the REX observation.
  15. Cartwright, R., Holler, B., Hendrix, A., et al., (including Grundy, W.), 2022, DPS, 54, 106.01, Hubble Space Telescope observations of the large moons of Uranus and implications for radiolytic processing and radiation darkening
    Clues regarding surface composition and surface processing (e.g., from magnetospheric interactions) can be gleaned from reflectance spectra spanning the near-ultraviolet (NUV, 200 400 nm) and visible (VIS, 400 700 nm) wavelength regions. For example, NUV and VIS spectra collected by the Space Telescope Imaging Spectrograph (STIS) and the (now defunct) Faint Object Spectrograph (FOS) on the Hubble Space Telescope (HST) have detected an absorption feature centered near 260 nm on the Galilean moon Ganymede and the Saturnian moons Dione and Rhea, attributed to O3 formed by charged particle interactions with H2O ice on their surfaces. In contrast to the Jupiter and Saturn systems, the extent of interactions between Uranus' magnetosphere and its moons is largely unknown. Measurements made by Voyager 2's magnetometer determined that Uranus' magnetic field axis is offset by 59 from the orbital plane of its major moons. Nevertheless, Voyager 2's Low Energy Charged Particle detector measured particle depletions associated with the orbits of these moons, indicative of charged particle interactions.

    Possible evidence for radiolytic processing of the Uranian moons was identified in spectra collected by FOS on HST (220 475 nm), which display absorption features centered near 280 nm on Ariel, Titania, and Oberon, attributed to trapped OH formed by charged particle interactions with H2O ice. The 280-nm band was found to be strongest on the inner moon Ariel and weaker on the outer moons Titania and Oberon, consistent with higher charged particle fluxes closer to Uranus. However, these prior observations did not sample both the leading and trailing hemispheres of the Uranian moons and did not observe Umbriel, orbiting between Ariel and Titania, reducing the utility of these data for understanding charged particle weathering.

    In this study, we are analyzing new HST/STIS spectra (200 570 nm) of the leading and trailing hemispheres of Ariel, Umbriel, Titania, and Oberon to assess the influence of charged particle bombardment. Our preliminary analysis indicates that the NUV spectral slopes are redder than the VIS spectral slopes in these STIS data. We also tentatively identify weak bands centered near 255 nm, which might result from O3. Furthermore, the NUV albedo of Oberon's leading hemisphere (0.252 0.05) is notably darker than its trailing hemisphere (0.278 0.05), consistent with the accumulation of dark material on its leading side that might have originated as dust grains on Uranus' retrograde irregular satellites. We will present the six STIS spectra collected so far and our ongoing analyses.

  16. Firgard, M., Kareta, T., 2022, DPS, 54, 109.01, Modeling Ice & Dust in C/2017 K2 (PanSTARRS)'s Coma
    C/2017 K2 (PanSTARRS) is an inbound long-period comet that has been active since 24 AU and likely as far out as 35 AU (Jewitt et al., 2017, 2021) well outside the water ice line. Near-Infrared (0.72.4 microns) spectroscopic observations were obtained with the SpeX instrument at the NASA Infrared Telescope Facility (IRTF) on 2021 April 30 at a heliocentric distance of ~6.5 AU that showed clear signs of water ice (Kareta et al., 2021) in its coma, which led us to begin a campaign to monitor K2 with the NIHTS instrument on the Lowell Discovery Telescope (LDT), including observations in March and June 2022, to further characterize the initially detected water ice. The SpeX data shows strong water ice absorption features at 1.5 and 2.0 microns with an overall red slope while the NIHTS data preliminarily shows much weaker ice bands. We ran several different spectral models utilizing a Markov Chain Monte Carlo approach to characterize the dust and ice in the coma. We found that several different combinations of parameters, such as Hapke vs. Mie scattering and linear vs. intimate mixing, resulted in different models that fit the data similarly well with different ice fractions ranging from ~7% to ~14%. Some of our models did, however, prefer large dust grains and small water ice grains, in line with interpretations of recent Hubble observations (Zhang et al., 2022). We discuss the most interesting of these models and compare them to those of other comets to better determine what causes comets to have ice in their comae. We also discuss our plans to model the NIHTS observations and collect more observations in the future.
  17. Diniega, S., Benecchi, S., Berdis, J., et al., (including Kareta, T.), 2022, DPS, 54, 214.04, Study Status Report from the DPS Meetings Exploration Team (DPS-MXT), and Request for Community Input
    In 2022, the DPS Committee convened a DPS Meetings Exploration Team (DPS-MXT/"DPS mixt") to identify options for future DPS fall meetings, so as to best serve the full DPS community. In particular, this team (consisting of the author list) considers different potential DPS meeting structures: i.e., fully virtual, in-person focused, or a hybrid meeting engaging both in-person and remote participants, and identifies the risks/costs/resources/benefits associated with each structure. This team will make next step recommendations to the DPS Committee for effective development of future DPS meetings, includingbut not limited toconsideration of hybrid meeting structures. Final output from this team will be delivered via a written report to the DPS Committee and DPS community by the end of calendar year 2022. More info can be found at https://dps.aas.org/meetings/dps-mxt.

    At the DPS 53 meeting, we will share our present study status, including results of the community survey issued in July. This survey included questions on personal recent meeting experiences and decision-making, broader-perspective thoughts regarding DPS meeting planning and investment, and self-reported identities and primary concerns of respondents. In addition to this, we have divided into small groups to look into: (1) hybrid poster options, (2) low-investment options for virtual participation in a primarily in-person focused meeting, (3) concerns and interests of exhibitors, (4) concerns and interests of those organizing splinter meetings, and (5) a review of past DPS post-meeting survey feedback.

    Finally, we will advertise opportunities at the DPS meeting to provide comments to DPS-MXT members, including but not limited to the relevant in-person and virtual sessions for this poster presentation. (And following the meeting, we will review the results of the DPS 53 post-meeting survey; please watch for its announcement and submit your comments.)

    Thank you to all in the community that have provided feedback and suggestions!

  18. McKinnon, W., Singer, K., Robbins, S., et al., (including Grundy, W.), 2022, DPS, 54, 303.03, Viscous relaxation of Oort and Edgeworth craters on Pluto: Possible indication of early high heat flows
    We use upper envelope, quantile regressions to estimate the depth-diameter relation for pristine complex craters on Pluto, based on the rim-to-floor depths in Robbins et al. (Icarus 356, 2020) derived from the New Horizons stereo DEM (Schenk et al., Icarus 314, 2018). Extrapolating to smaller craters, and assuming a depth/diameter for simple craters on Pluto of 0.2, we estimate a simple-to-complex transition between 7.5 and 11.5 km diameter a range consistent with the morphological transitions quantified in Robbins et al. Other than the Sputnik and Burney basins, the largest identified craters on the encounter hemisphere are 80-km Elliot, 115-km Oort, and 140-km Edgeworth. Notably, they are all anomalously shallow compared with our derived depth-diameter relations. Elliot is infilled with bright (CH4- and presumably N2-rich) ice, which can account for its shallowness. Edgeworth on the other hand is particularly shallow, and its floor appears bowed up above the original ground plane, a classic hallmark of viscous relaxation in a surface whose viscosity decreases rapidly with depth. We estimate a pristine (immediate post-impact) depth for Edgeworth of at least 6.2 km, which when compared with its present depth of ~1 km implies a relaxation fraction (RF) of at least 84%. Oort is intermediate, and if its depth of 2.4 km is due to viscous relaxation, then its RF is at least 57%. The difference in RF (and morphology) between the two is somewhat puzzling, as both craters lie in dark, western Cthulhu, and are similar enough in size, location (only 400 km apart), and apparent age (morphological preservation) that one suspects they resulted from the impact of a (tight) Kuiper belt binary. But we have no explicit evidence that they are in fact coeval. Possibly Oort is somewhat younger and was less affected by an early epoch of high heat flow. Finite element calculations show that this heat flow would have to have been substantial, far above steady-state radiogenic values. Such constraints are always subject to uncertainties in the subsurface conductivity structure, however. We expect fracturing and porosity to accompany complex crater formation and collapse, reducing thermal conductivity, but interstitial subsurface nitrogen (gas and possibly liquid) may compensate.
  19. Raut, U., Teolis, B., Kammer, J., et al., (including Grundy, W.), 2022, DPS, 54, 303.04, Sure the red cap is fascinating, but what of Charon's gray cloak?
    While it is difficult to not be mesmerized by Charon's red polar cap, the subtle grey tone masking the lower latitude regions [1-6] is equally interesting, beseeching an explanation. Recent results from laboratory experiments combined with exospheric modeling [7, 8] provide insightful clues to the origin of Charon's colorful landscape. Dynamic interplanetary medium Lyman- (IPM Ly-) photolysis of Plutonian methane accreting at seasonally-varying rates imprints a latitude-dependent compositional complexity gradient onto the winter hemisphere [7]. The photolyzed polar frost is primarily ethane while the lower latitudes harbor the more complex, less volatile, refractories. We posit that solar wind (SW) processing following spring sunrise converts polar ethane to tholin-like refractories which may impart the red hue to the Mordor Macula region. SW radiolysis could also dehydrogenate the already-complex photoproducts [9-13] at lower latitudes reducing them to carbon-rich species likely responsible for Charon's gray shade. We will estimate the relative abundance of this neutral gray absorber needed to explain Charon's low visible albedo [14, 15] and assess the timescales required to accumulate such abundances through successive cycles of IPM photolysis and SW radiolysis.

    [1] Stern et al., Science, 350, 6258, 2015 [2] Cruikshank et al., Icarus, 246, 82-92, 2015 [3] Grundy et al., Science, 351, 6279, 2016 [4] Grundy et al., Nature, 539, 65-68, 2016 [5] Protopapa et al., in The Pluto System after New Horizons, 433-456, 2021 [6] Howett et al., in The Pluto System after New Horizons, 413-432, 2021 [7] Raut et al., Science Advances, 8, 24, 2022 [8] Teolis et al., Geophysical Research Letters, 49, 8, 2022 [9] Compagnini et al., Carbon, 47, 6, 2009 [10] Foti et al., NIM B, 24-25, 522-525, 1987 [11] Brown et al., NIM B: 24-35, 1, 512-516, 1987 [12] Thompson et al., JGR: Space Physics, 92, A13, 14933-14947, 1987 [13] Moore, M. H. and Hudson R.L., Icarus, 135, 2, 518-527, 1998 [14] Buratti et al., Astrophysical Journal Letters, 874, L3, 2019 [15] Tholen, D.J. and Buie, M. W., Astronomical Journal, 96, 1977-1982, 1989.

  20. Young, L., Buie, M., Keeney, B., et al., (including Wasserman, L.), 2022, DPS, 54, 307.03, Report on the 2022 June 1 UT occultation by Pluto from Australia and Indonesia
    Pluto occulted a RP=12.2 magnitude star (Gaia EDR3 6852184815383389824) on 2022 June 1 UT. We attempted observations from four sites in Indonesia (with success at Timau and ITERA), and from eleven sites in Australia (with success at Bloomsbury, QLD; Darwin, NT; Jabiru, NT; and eight portable sites with near Katherine, NT as part of picket fence with 15-km cross-track spacing near the predicted centerline). We observed lightcurves both north and south of the centerline and several within the central flash zone. Two co-located telescopes observed a narrow, single-peaked, central flash roughly 2.5 times brighter than the unocculted stellar level. The co-located telescopes were equipped long-pass and short-pass filters with cut-off/cut-on wavelengths at 600 nm. Preliminary results show that the NIMAv9PLU055 prediction from the Lucky Star team (https://lesia.obspm.fr/lucky-star/occ.php?p=105008) was extremely accurate. We will report on the progress of our analysis of changes in the pressure and temperature of Pluto's atmosphere and its behavior of its lowest altitudes. This work was funded by NASA SSO 80NSSC19K0824.
  21. Gustafsson, A., Protopapa, S., Grundy, W., et al., 2022, DPS, 54, 307.05, Spatial Distribution and Secular Evolution of Pluto's Ices as seen from IRTF/SpeX
    NASA's New Horizons mission has revealed the complex cryogenic world of Pluto (Stern et al. 2015, Science 350). The spatial heterogeneity of this large trans-Neptunian object results from a variety of processes, including the seasonal transport of nitrogen (N2), methane (CH4), and carbon monoxide (CO) ices. All three ices are indeed mobile at Pluto's surface temperature of ~40K, with CO and N2 being much more volatile than CH4. Over seasonal timescales, varying patterns of insolation are thought to cause sublimation and redistribution of these volatile ices.

    While New Horizons returned a detailed, up-close snapshot of Pluto in 2015 (Stern et al. 2015, Science 350), a broad seasonal context is needed to improve our understanding of the processes responsible for Pluto's evolution. This can only be achieved through analysis of data that monitor Pluto over timescales of years. We present an extension of the analysis of the IRTF/SpeX data spanning the timeframe from 2001 to 2013 (Grundy et al. 2013, Icarus 223; Grundy et al. 2014, Icarus 235) to now include data up through 2021. This study relies on the evaluation of spectral parameters, including band depth and equivalent width. In addition, we have systematically modeled all IRTF/SpeX data with a modern radiative transfer code (Hapke 2012, Icarus 221; Protopapa et al. 2017, Icarus 287). This enables us to interpret the varying spectral profile of Pluto across the full data set in terms of variations in mixing ratio and/or path length of Pluto's volatile ices. Pluto's composition derived from the IRTF/SpeX ground-based measurements acquired in 2015 will be compared with the New Horizons composition maps of Pluto (e.g., Protopapa et al. 2017, Icarus 287; Gabasova et al. 2021, Icarus 356), permitting direct linkage between spectral features in disk integrated spectra and geological units revealed by New Horizons. Overall, this work will shed light onto the role played by each volatile ice in shaping the surface composition of Pluto and its temporal evolution over a two decade-long time period.

    This work was funded by the NASA Solar System Workings and New Frontiers Data Analysis Program via contracts 80NSSC19K0554 and 80NSSC19K0821 to SwRI (PI: Protopapa).

  22. Verbiscer, A., Benecchi, S., Denk, T., et al., (including Grundy, W.), 2022, DPS, 54, 308.03, Saturn's Irregular Satellites at True Opposition
    In August 2021, five of Saturn's irregular satellites were perfectly aligned with the Earth and Sun at "true" opposition. We observed Albiorix, Kiviuq, Palliaq, Siarnaq, and Tarvos from SOAR for five nights using the Goodman imaging spectrograph to measure their opposition effects. The opposition effect, or surge, is the non-linear increase in reflectance seen as an object nears opposition and the solar phase (Sun-target-observer) angle decreases. The smallest phase angles are attainable at node crossings when the Earth transits the solar disk as viewed from the object. In this configuration, a solar system body is at "true" opposition. When combined with observations at larger solar phase angles, the resulting measurement can be related to the collisional history and physical properties of the surface. These observations enhance the scientific return from the NASA/ESA Cassini Mission to Saturn and cannot be repeated until 2049. This work is funded by NASA SSO 80NSSC21K0433.
  23. Schleicher, D., Knight, M., Skiff, B., et al., (including Bair, A.), 2022, DPS, 54, 309.03, Physical Properties of Comet 28P/Neujmin 1: Nucleus Rotation, Shape, and Phase Function
    We performed imaging of 28P/Neujmin 1's nucleus during a 5-month interval beginning in late 2021 through April 2022, with the comet's heliocentric distance increasing from 3.0 to 4.1 AU following its unobservable perihelion passage early in 2021. Since Neujmin 1 has an unusually long orbital period of 18.2 yrs for a Jupiter family object, few opportunities for study have occurred in the modern era. The first studies for this very anemic object were in 1984, when visible and thermal photometry were obtained less than two months prior to perihelion. The lack of a dust coma (though gas was detected) permitted the first comet nucleus albedo measurements to be made and revealed a large nucleus and a very low albedo prior to the Halley mission findings. Observations in following years revealed a double-peaked rotational lighcurve and a period near 12.7 hr.

    Preliminary results from our recent observational campaign of Neujmin 1 reveal a slowly varying lightcurve amplitude ranging from 0.5 to 0.7 mag, significantly greater than complete lightcurves obtained during prior decades, strongly implying that our viewing geometry of the nucleus was from much closer to the equator. The measured (synodic) period of 12.7150.003 hr is the most precise value ever determined and, given the quite large nucleus size (effective radius of ~10.7 km) and the extremely low active fraction (<0.1%), we assume the sidereal period is unchanged since the 1980s. Although the range of phase angles was limited, ranging from 14.7 to 6.0 and back to 14.6 deg, the ensemble of data during 20 nights of observations yielded a tight constraint on the nucleus linear phase function coefficient of ~0.05 mag/deg, somewhat steeper than the average value of 0.04 mag/deg for comet nuclei.

    Details of these and other results will be presented. This research was supported by NASA's Solar System Observations Program grant 80NSSC18K0856.

  24. Raposa, S., Tan, S., Grundy, W., et al., 2022, DPS, 54, 318.01, Phase Behaviors of Pluto's Volatiles
    Nitrogen (N2), methane (CH4), and carbon monoxide (CO) are the most abundant volatiles on Pluto, Triton, Eris, and Makemake. Pluto's Sputnik Planitia, for example, is a giant reservoir of these volatiles. It is important to understand the phase behaviors of mixtures, as they directly affect how a surface evolves and/or interacts with the atmosphere. This study aims to quantify and map the phase diagrams of this ternary chemical system as a function of temperature, pressure, and composition using two experimental methods run in the Astrophysical Materials Laboratory at NAU, starting with multiphase experiments for the three constituting binary systems (N2 + CO, CO + CH4, N2 + CH4). Notably, there are gaps in planetary materials and ice databases, particularly in phases of ices and compositions of mixtures. The first method cools a single composition slowly, using Raman spectroscopy to detect where phase changes occur within the system. This method (the "isoplethic method") allows us to obtain temperatures of the phase boundaries for each composition. We then plot the phase-change locations on the corresponding binary phase diagram. Collecting data at multiple compositions is time consuming and expensive, so we couple this method with a second method that alternately applies gas injections with cooling along the three-phase vapor-liquid-solid equilibrium curve on the temperature-pressure phase diagram. This method is advantageous because it allows for more efficient collection of data points at multiple compositions along the three-phase equilibrium curve relative to the isoplethic method. We have performed the second method for all three binary systems, and the results are recently published (doi: 10.1063/5.0097465). These laboratory methods are being compared and their results are modeled using a thermodynamic equation of state, CRYOCHEM, which is based on the Thermodynamic Perturbation Theory (TPT) by coupling the Perturbed-Chain Statistical Associating Fluid Theory (PCSAFT) for the fluid part with the Lennard-Jones Weeks-Chandler-Andersen approach for the solid part. We fine-tune the solid-phase binary interaction parameters in this model with the laboratory data, and the model will ultimately provide the compositions and densities of the equilibrium phases for use by the community in various application models (e.g., geophysical models, global circulation models, and sublimation-condensation evolution models).
  25. Thieberger, C., Hanley, J., Corlies, P., 2022, DPS, 54, 408.01, Constraining the Vertical Abundances of Haze and Methane on Titan
    Saturn's largest moon, Titan, hosts a substantial atmosphere rich with complex chemistry. While its constituents are predominantly nitrogen and methane, Titan's upper atmosphere receives abundant UV radiation. This results in the photolysis of methane into higher order hydrocarbons that are subsequently processed to form a complex aerosol distribution on Titan. In order to better constrain the vertical abundances and compositions of these hazes, we conducted a series of disk-integrated observations of Titan with the Lowell Discovery Telescope (LDT). Observations with the EXtreme PREcision Spectrometer (EXPRES) captured not only broadband spectral slopes set by absorption of UV and visible light by aerosols in Titan's upper and middle atmosphere, but also very high spectral resolution absorption features. One example is the ability to measure the slope, shape, and strength of the 620nm methane absorption feature, which will allow for sensitive constraints on the vertical distribution of methane in Titan's atmosphere. To complement these observations, we also used the Near-Infrared High-Throughput Spectrograph (NIHTS) on LDT to study four methane windows (0.938, 1.1, 1.3, and 1.6-m) that can see all the way down to Titan's surface. This alloweds us to obtain and analyze vertical abundances of methane and hazes through Titan's entire atmosphere. By studying both broadband and narrow features from EXPRES in conjunction with precise methane windows from NIHTS, we will be able to address ongoing science questions regarding Titan's atmospheric chemistry. In particular, we will present our observations of longitudinal variations in Titan's haze distribution and abundances by comparing observed spectra centered on various longitudes across Titan.
  26. Nelsen, M., Ragozzine, D., Giforos, W., et al., (including Grundy, W.), 2022, DPS, 54, 410.06, Constraints on the Orbit of the Moon of Mid-Size TNO 2013 FY27
    The Trans-Neptunian Object (TNO) 2013 FY27 has an ALMA-estimated diameter of 765+80-85 km, placing it in the transition between small low-density TNOs and large high-density TNOs. It is similar to "mid-size" TNOs 2002 UX25 and 2007 UK126 (Gkun'homdima and Go'e Hu). Since the cosmochemical abundance is expected to be reasonably well-mixed among TNOs, a leading hypothesis for the density transition is that mid-sized objects are smaller and able to retain a significant porosity (50-90%), suggesting they were never heated. Better understanding this transition and its implication for TNO formation requires expanding the number of mid-size TNOs with well-measured densities. Although 2013 FY27 has a known moon and multiple epochs of HST data, its orbit has remained elusive. The moon is faint (delta magnitude of 3.0) and never seen more than 0.25 arcseconds away and highly blended in most epochs suggesting an edge-on orbit. A common approximation for non-detections is to assume relative astrometric position of 0 with uncertainties roughly encompassing the area where the satellite could have been seen. With ~half of the relatively few epochs showing non-detections, we have developed a new technique within our PSF-fitting code "nPSF" to return a "likelihood map", marginalized over the expected brightness of the moon, that more precisely represents the result of weak or non-detections. Combining this with our TNO binary orbit fitting tool MultiMoon, we will provide updated orbital constraints on the density of FY27 with implications for mid-size TNOs.
  27. Bair, A., Schleicher, D., Knight, M., et al., (including Skiff, B.), 2022, DPS, 54, 411.03, A Collection of Narrowband Photometry and Imaging of Comets: Results from PanSTARRS (C/2017 K2), 67P/Churyumov-Gerasimenko, 38P/Stephan-Oterma, and 64P/Swift-Gehrels
    We will report on preliminary results from narrowband filter photometry and imaging of four comets observed at Lowell Observatory. The dynamically new Comet PanSTARRS (C/2017 K2) was discovered 5 years ago at 21st mag and a distance of 16 AU, and our first successful production rate measurements, for the molecules C2 and CN, occurred in October 2021 when it had reached 5.2 AU. Its very high dust-to-gas ratio made continuum subtraction more difficult than usual, precluding any earlier definitive detections; the remaining gas species (OH, NH, and C3) were measured by spring 2021 when PanSTARRS was at 3.1 AU. Our dust and CN imaging have not yet revealed any jet-like morphology, possibly indicative that this body is really on its first close approach to the Sun.

    We have now observed the Jupiter-family comet 67P/Churyumov-Gerasimenko (C-G) during 5 apparitions, with its most recent appearance in 2021/22 being its best since 1982. This comprehensive data set confirms previous findings, including its large pre-/post-perihelion asymmetry in production rates, with individual gas species ranging from 2 to nearly 6 higher after perihelion than before. For dust, there is a large trend with aperture size making seasonal comparisons less clear. Unexpectedly, C-G had production rates 1.5-2.5 higher before and surrounding perihelion during 2021/22 as compared to previous apparitions, while as the comet receded the rates dropped to levels similar to prior apparitions.

    During 2018/19, comets 38P/Stephan-Oterma (S-O) and 64P/Swift-Gehrels (S-G) had their most viable apparitions since the early 1980s. The Halley-type comet S-O has an orbital period of 38 years, and we have production rates for 7 months surrounding perihelion during both the 1980/81 and 2018/19 apparitions. The comet reached peak production rates during the month prior to its closest approach, and the individual gas species range from 1.5-3 higher before perihelion than after. We additionally see a secular decrease in production rates for S-O, with values 1.5-2.5 lower in 2018/19. Jupiter-family comet S-G has an orbital period of 9.4 years, and we obtained about 7 months of observations surrounding its closest approach in late 2018. S-G shows strong pre-/post-perihelion asymmetry, with peak production occurring approximately one month after perihelion. Its post-perihelion production rates are 2-8 higher for the individual gas species, and 3-5 higher for dust than they were prior to perihelion.

    These and additional results will be presented. This work was supported by NASA Solar System Observations Program grant 80NSSC18K0856.

  28. Trujillo, C., Trilling, D., Chandler, C., et al., (including Mommert, M.), 2022, DPS, 54, 501.01, DECam Ecliptic Exploration Project (DEEP) Observational Program
    The multi-year observational campaign for the DECam Ecliptic Exploration Project (DEEP) is nearly complete with over 90 nights of observations scheduled using the Cerro Tololo Blanco 4 meter telescope, primarily in half-night increments. With a limiting magnitude of V of about 26.5, after digital tracking, covering over 35 square degrees, DEEP is among the faintest surveys sensitive to Trans-Neptunian Objects (TNOs) to date. We expect to discover and perform orbital characterization for thousands of TNOs in this survey, more than doubling the known population. Here, we summarize the observations that have taken place including the cadence of observations, sky areas searched, image quality and depth achieved. In addition, we discuss how our observations have met the expectations originally laid out in our plan, or in some cases, presented us with challenges, such as navigating the shutdown of many astronomical observatories for the COVID pandemic and a move to largely remote data collection once observatories were back in operation.
  29. Strauss, R., Trilling, D., Gerdes, D., et al., (including Mommert, M.), 2022, DPS, 54, 501.03, Constraining the shape distribution of TNOs with DEEP
    The DECam Ecliptic Exploration Project (DEEP) is a wide-field survey of the outer solar system, covering more than 120 square degrees of sky and achieving a single-exposure depth of R~24, and with digital tracking techniques, a maximum depth fainter than R~26.5. Each epoch of DEEP observing provides a series of 100 two-minute images of each DEEP field.

    We present the methods and results from the first year of DEEP single-exposure TNO discoveries. The primary result from the first year of single exposure detections are fast-cadence lightcurves with a four-hour photometric baseline for ~30 new TNOs, a significant supplement to the existing set of TNO lightcurves in the literature. We discuss methods by which these transient sources are identified, vetted, and processed within the images. We will present implications of some of the most interesting and high-amplitude individual rotational lightcurves, as well as the constraints on the overall TNO shape distribution provided by our set of partial lightcurves, which are consistent with a high incidence of very elongated objects. This work is supported by grants from both NASA and NSF.

  30. Bernardinelli, P., Smotherman, H., Portillo, S., et al., (including Mommert, M.), 2022, DPS, 54, 501.05, First multi-night results from the DECam Ecliptic Exploration Project (DEEP)
    We present the first set of 109 trans-Neptunian objects (TNOs) linked across data taken between 2019-2021 from the DECam Ecliptic Exploration Project (DEEP). Of these 109 TNOs, we have not been able to match 105 to previously known TNOs. Each individual detection for our objects was recovered in a digital tracking search for TNOs using two to four hour exposure sets, and the detections were subsequently linked across multiple observing seasons. The final orbits use a specialized orbit fitting procedure that accounts for the positional errors derived from the digital tracking procedure. In addition to this catalog, we also present our survey simulator, a software routine that allows the user to directly determine which members of a synthetic population would be detectable by the survey, and thus allows for direct comparison between models and data. Combining these tools with a comprehensive set of synthetic objects injected into our images and recovered in a blind search, we determined our magnitude of 25% efficiency to be mVR = 26.2 for the multi-year data in this DEEP quadrant, with an overall efficiency for bright objects inside our pointing groups is 78%. Early results include a mid-a object found at 78 au, robust orbits and magnitudes for H ~ 10 classical TNOs and preliminary inferences on the structure of the Kuiper belt.
  31. Chandler, C., Trujillo, C., Kueny, J., et al., 2022, DPS, 54, 502.01, Active Asteroids Citizen Science: First Year Results
    We present results from the first year of our Citizen Science project Active Asteroids (http://activeasteroids.net), a NASA Partner. The project, hosted on the Zooniverse platform, engages the public through a search for minor planets displaying activity such as tails or comae. Of particular interest are active asteroids, objects that teach us about the solar system volatile distribution, knowledge important for future space exploration and our understanding of the origins of terrestrial water. However, studying active asteroids has proven challenging because they are rare, with fewer than 30 found since the first was discovered in 1949. To facilitate the discovery of additional active asteroids we ask volunteers to look for activity in images of known minor planets that we extract from publicly available Dark Energy Camera data.

    Project preparations have already yielded several results, including the discovery of a new active Centaur, now identified C/2014 OG392 (PANSTARRS), characterization of active asteroids (6478) Gault and (248370) 2005 QN173, and constraints on the asteroid activity occurrence rate. Since the 31 August 2021 launch of Active Asteroids over 6,000 project volunteers have examined over 187,000 images. These efforts have yielded numerous candidate active objects which we are actively investigating. Here we provide an introduction to the Active Asteroids project, present results stemming from the first year of operations, and discuss future plans for the program.

    This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under grant No. 2018258765 (COC) and grant No. 2020303693 (JKK). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Funded in part by NASA grant No. 80NSSC19K0869 and NASA grant No. 80NSSC21K0114.

  32. Moskovitz, N., Kareta, T., Naidu, S., et al., 2022, DPS, 54, 505.02, Pre- and post-impact observations of Didymos in support of NASA's DART mission
    On 26 September 2022, as NASA's first planetary defense test mission, the DART spacecraft will intentionally impact the smaller member (named Dimorphos) of the binary near-Earth asteroid Didymos. In addition to energy from the spacecraft, ejecta removed by the impact will impart momentum to Dimorphos and change its orbital period around Didymos. The baseline requirement for the mission is to change the orbital period by at least 73 seconds. This change will allow direct measurement of the so-called beta parameter, or the momentum enhancement caused by escaping ejecta.

    For this experiment to be successful, the pre-impact orbital state of Dimorphos must be well constrained. Measuring successive mutual events (eclipses and occultations) has served as the primary method to derive these constraints (Pravec et al. 2006, 2022). We will present a synthesis of mutual event detections from multiple apparitions that have contributed to understanding the pre-impact state of the system (Naidu et al. 2022, Scheirich & Pravec 2022). We will show that the most recent observations from July 2022 confirmed the reference orbit of Dimorphos and reduced the formal uncertainty of its orbital phase at the time of impact to 3.9 degrees, which is more than 10x smaller than the baseline requirement set by the mission.

    Following impact, the ejecta may obscure the system for days or even weeks, and thus preclude measurement of mutual events. As such it is unlikely that a post-impact orbit solution based on new mutual event detections will be available at the time of the meeting. However, monitoring of the ejecta will be an important post-impact activity. We will present preliminary results from a coordinated ejecta monitoring campaign at the 4.1-m Southern Astrophysical Research (SOAR) telescope, Lowell Observatory's 1.1-m Hall telescope, and the 4.3-m Lowell Discovery Telescope (LDT). This monitoring campaign will include measuring photometric colors and morphology of the ejecta cloud as a means to constrain key properties such as particle size and the dynamics of released particles. These observations are planned to probe a range of timescales (hours, days, weeks) and will directly complement other observations carried out by the DART investigation team.

  33. Engle, A., Hanley, J., Thieberger, C., et al., (including Grundy, W.), 2022, DPS, 54, 509.02, Adding Propane to the MethaneEthaneNitrogen System at Titan-like Conditions
    Saturn's largest moon, Titan, is shrouded in a thick nitrogen-rich (N2) atmosphere that supports ongoing methane (CH4) photochemistry, with two of the principal products being ethane (C2H6) and propane (C3H8). Methane, ethane, and dissolved atmospheric nitrogen make up the bulk composition of the polar lakes, and it is suspected that a trace amount of propane resides in them as well. It is likely that even small quantities of C3H8 affects phase behavior, physical properties, and the N2 content of the CH4C2H6N2 system, producing phenomena that have not yet been experimentally mapped.

    The Astrophysical Materials Lab Group at Northern Arizona University has initiated a study to investigate such behaviors within the CH4C2H6C3H8N2 system. The results showcase the difference between the ternary and quaternary systems and may provide a deeper understanding in the coupled chemical-dynamical behavior of Titan's lakes.

    The work leading up to this study involved recording the changes in freezing point temperatures of the CH4C2H6 system when N2 is added, as well as the temperature at which a second liquid forms. The present work with C3H8 follows the same process as the CH4C2H6N2 experiments in which the alkane mixture is released into the cell as a liquid at 95 K and is then followed by the introduction of gaseous N2 into the system. The N2 is used to maintain a constant vapor pressure of 1.5 bar, simulating both Titan's surface pressure and its N2-rich atmosphere. The temperature in the cell is incrementally lowered until the first ice is witnessed. N2 dissolution increases as temperature decreases and so more of it must be added as the experiment progresses to maintain constant vapor pressure. So, while the total concentration of the sample changes throughout the experiment, the relative alkane ratio remains the same. Using this process, the freezing point temperatures, the changes in N2 concentration, and the condition for the appearance of the two liquids are recorded and then compared to the ternary results. The comparisons can then demonstrate the impact of C3H8 on the CH4C2H6N2 system.

  34. Kareta, T., Moskovitz, N., Sharkey, B., 2022, DPS, 54, 514.06, Moon Rocks in the Mission Accessible Near-Earth Object Survey Sample
    The Mission Accessible Near-Earth Object Survey (MANOS) is focused on identifying and characterizing potential future spacecraft targets and has built a sample of about a thousand NEOs with techniques including light curves, colors, and spectroscopy since its inception a decade ago. The survey's focus on objects with relatively similar orbits to the Earth (and thus low relative velocities) means that a fraction of the sample is likely lunar ejecta and space junk, as opposed to NEOs with origins in the Main Belt. Separating out these interlopers is critical to ongoing efforts to understand the distribution of properties in the whole (asteroidal) MANOS sample, but also means that we have built a catalog of physical properties for these 'non-traditional' NEOs. This set of properties can aid in future discrimination of such objects.

    We will present on efforts to identify these interloping objects within the sample both through dynamical and physical means, and on the tools we've developed to do so that may be of use to others. There is not a simple rule to identify the origins of objects with such Earth-like orbits, and thus care must be taken with each object to avoid misclassifying it. Below a cut-off velocity-at-infinity of 2.5 km/s, our sample has 50 objects, at least 35 of which have at least a partial light curve and 15 of which have visible reflectance spectra. We will compare the rotational and surface properties of the objects in our sample to small NEOs of similar sizes, to reflectance spectra of lunar materials, and to those of (469219) Kamo'oalewa, which was recently proposed to be lunar ejecta. We will also compare the properties of this sub-sample to those within the entire MANOS catalog, with the larger aim of understanding the diversity of properties for objects with a lunar origin. This will have implications for understanding the compositional breakdown of NEOs on earth-like orbits, which is key information for applications of in situ resource utilization and impact hazard assessment.

  35. Pinilla-Alonso, N., Popescu, M., Licandro, J., et al., (including Grundy, W.), 2022, PSJ, 3, 267, Detection of the Irregular Shape of the Southern Limb of Menoetius from Observations of the 2017-2018 Patroclus-Menoetius Mutual Events
    This work presents the analysis of seven mutual events of the Patroclus-Menoetius system (PMS) observed during the last season of mutual events, in 2017-2018. We compare the obtained light curves with those predicted using Grundy et al. and discuss the differences in the timing of the events and the drop of magnitude. Based on models of these observations, we present a collection of orbital parameters that provide the best fit for the observed events and compare the new solutions for the orbit of the system with solutions provided in the literature. Furthermore, we also discuss an interesting finding in the light curve of the only superior event in our collection. This light curve (the one with the best signal-to-noise ratio in our data set) shows the imprint of a possible crater in the south pole of Menoetius as deep as a fourth of its radius.
  36. Pan, J., Lin, H., Gerdes, D., et al., (including Kuehn, K.), 2022, PSJ, 3, 269, Photometric Properties of Jupiter Trojans Detected by the Dark Energy Survey
    The Jupiter Trojans are a large group of asteroids that are coorbiting with Jupiter near its L4 and L5 Lagrange points. The study of Jupiter Trojans is crucial for testing different models of planet formation that are directly related to our understanding of solar system evolution. In this work, we select known Jupiter Trojans listed by the Minor Planet Center from the full six years data set (Y6) of the Dark Energy Survey (DES) to analyze their photometric properties. The DES data allow us to study Jupiter Trojans with a fainter magnitude limit than previous studies in a homogeneous survey with griz band measurements. We extract a final catalog of 573 unique Jupiter Trojans. Our sample include 547 asteroids belonging to L5. This is one of the largest analyzed samples for this group. By comparing with the data reported by other surveys we found that the color distribution of L5 Trojans is similar to that of L4 Trojans. We find that L5 Trojans' g - i and g - r colors become less red with fainter absolute magnitudes, a trend also seen in L4 Trojans. Both the L4 and L5 clouds consistently show such a color-size correlation over an absolute magnitude range 11 < H < 18. We also use DES colors to perform taxonomic classifications. C- and P-type asteroids outnumber D-type asteroids in the L5 Trojans DES sample, which have diameters in the 5-20 km range. This is consistent with the color-size correlation.
  37. Chan, K., Avila, S., Carnero Rosell, A., et al., (including Kuehn, K.), 2022, PhRvD, 106, 123502, Dark Energy Survey Year 3 results: Measurement of the baryon acoustic oscillations with three-dimensional clustering
    The three-dimensional correlation function offers an effective way to summarize the correlation of the large-scale structure even for imaging galaxy surveys. We have applied the projected three-dimensional correlation function, p to measure the baryonic acoustic oscillations (BAO) scale on the first-three years Dark Energy Survey data. The sample consists of about 7 million galaxies in the redshift range 0.6 <zp<1.1 over a footprint of 4108 deg2. Our theory modeling includes the impact of realistic true redshift distributions beyond Gaussian photo-z approximation. p is obtained by projecting the three-dimensional correlation to the transverse direction. To increase the signal-to-noise of the measurements, we have considered a Gaussian stacking window function in place of the commonly used top-hat. p is sensitive to DM(zeff)/rs, the ratio between the comoving angular diameter distance and the sound horizon. Using the full sample, DM(zeff)/rs is constrained to be 19.00 0.67 (top-hat) and 19.15 0.58 (Gaussian) at zeff=0.835 . The constraint is weaker than the angular correlation w constraint (18.84 0.50 ), and we trace this to the fact that the BAO signals are heterogeneous across redshift. While p responds to the heterogeneous signals by enlarging the error bar, w can still give a tight bound on DM/rs in this case. When a homogeneous BAO-signal subsample in the range 0.7 <zp<1.0 (zeff=0.845 ) is considered, p yields 19.80 0.67 (top-hat) and 19.84 0.53 (Gaussian). The latter is mildly stronger than the w constraint (19.86 0.55 ). We find that the p results are more sensitive to photo-z errors than w because p keeps the three-dimensional clustering information causing it to be more prone to photo-z noise. The Gaussian window gives more robust results than the top-hat as the former is designed to suppress the low signal modes. p and the angular statistics such as w have their own pros and cons, and they serve an important crosscheck with each other.
  38. Dixon, M., Lidman, C., Mould, J., et al., (including Kuehn, K.), 2022, MNRAS, 517, 4291, Using host galaxy spectroscopy to explore systematics in the standardization of Type Ia supernovae
    We use stacked spectra of the host galaxies of photometrically identified Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) to search for correlations between Hubble diagram residuals and the spectral properties of the host galaxies. Utilizing full spectrum fitting techniques on stacked spectra binned by Hubble residual, we find no evidence for trends between Hubble residuals and properties of the host galaxies that rely on spectral absorption features (<1.3), such as stellar population age, metallicity, and mass-to-light ratio. However, we find significant trends between the Hubble residuals and the strengths of [O II] (4.4) and the Balmer emission lines (3). These trends are weaker than the well-known trend between Hubble residuals and host galaxy stellar mass (7.2) that is derived from broad-band photometry. After light-curve corrections, we see fainter SNe Ia residing in galaxies with larger line strengths. We also find a trend (3) between Hubble residual and the Balmer decrement (a measure of reddening by dust) using H and H . The trend, quantified by correlation coefficients, is slightly more significant in the redder SNe Ia, suggesting that the bluer SNe Ia are relatively unaffected by dust in the interstellar medium of the host and that dust contributes to current Hubble diagram scatter impacting the measurement of cosmological parameters.
  39. Lisse, C., Steckloff, J., Prialnik, D., et al., (including Kareta, T.), 2022, PSJ, 3, 251, 29P/Schwassmann-Wachmann 1: A Rosetta Stone for Amorphous Water Ice and CO CO2 Conversion in Centaurs and Comets?
    Centaur 29P/Schwassmann-Wachmann 1 (SW1) is a highly active object orbiting in the transitional "Gateway" region between the Centaur and Jupiter-family comet (JFC) regions. SW1 is unique among the Centaurs in that it experiences quasi-regular major outbursts and produces CO emission continuously; however, the source of the CO is unclear. We argue that, due to its very large size (~32 km radius), SW1 is likely still responding, via amorphous water ice (AWI) conversion to crystalline water ice (CWI), to the "sudden" change in its external thermal environment produced by its Myrs-long dynamical migration from the Kuiper Belt to its current location at the inner edge of the Centaur region. It is this conversion process that is the source of the abundant CO and dust released from the object during its quiescent and outburst phases. If correct, these arguments have a number of important predictions testable via remote sensing and in situ spacecraft characterization, including the quick release on Myr timescales of CO from AWI conversion for any few kilometer-scale scattered disk Kuiper Belt Objects transiting into the inner system; that to date SW1 has only converted between 50% and 65% of its nuclear AWI to CWI; that volume changes on AWI conversion could have caused subsidence and cave-ins, but not significant mass wasting or crater loss; that SW1's coma should contain abundant amounts of CWI+CO2 "dust" particles; and that when SW1 transits into the inner system within the next 10,000 yr, it will be a very different kind of JFC.
  40. Jin, M., Loyd, P., Boro Saikia, S., et al., (including Llama, J.), 2022, csss, 49, Modeling Coronal Mass Ejection Induced Dimmings on Epsilon Eridani and Comparing with HST Far-Ultraviolet Observations
    Although solar flares and CMEs are highly relevant phenomenona on the Sun, heliophysics studies have shown that they impact the planets in the solar system in different ways. CMEs have a much larger influence than flares on stellar evolution through mass loss and angular-momentum loss, and can significantly impact the habitability of exoplanets due to their ability to erode atmospheres of exoplanets. Even though the stellar flares are frequently observed, it remains challenging to associate stellar CMEs with any of these flares. CME-induced coronal dimmings (caused by the mass loss of coronal plasmas), which have been extensively observed on the Sun, are believed to be a promising proxy for detecting stellar CMEs. In this study, we present global MHD modeling results of CME-induced coronal dimmings on K dwarf star Epsilon Eridani. The Zeeman Doppler Imaging surface magnetic map of the star is used to drive the inner boundary condition of the model. The coronal heating parameters of the model are also constrained by the Emission Measure distributions derived from the previous EUVE and XMM observations. By initiating a CME eruption through analytical flux rope insertion, we simulate the coronal dimming evolution and calculate synthetic EUV/FUV line intensities with different emission temperatures. Furthermore, we present a coronal dimming analysis of Fe XII 1349 A and Fe XXI 1354 A emission from Epsilon Eridani with archival FUV observations by Hubble Space Telescope's Cosmic Origins Spectrograph and compare with the synthesized line emission in the model. Based on the result, we discuss the CME and wind contributions to the spin down and high observed mass loss rate from Epsilon Eridani.
  41. Porredon, A., Crocce, M., Elvin-Poole, J., et al., (including Kuehn, K.), 2022, PhRvD, 106, 103530, Dark Energy Survey Year 3 results: Cosmological constraints from galaxy clustering and galaxy-galaxy lensing using the MAGLIM lens sample
    The cosmological information extracted from photometric surveys is most robust when multiple probes of the large scale structure of the Universe are used. Two of the most sensitive probes are the clustering of galaxies and the tangential shear of background galaxy shapes produced by those foreground galaxies, so-called galaxy-galaxy lensing. Combining the measurements of these two two-point functions leads to cosmological constraints that are independent of the way galaxies trace matter (the galaxy bias factor). The optimal choice of foreground, or lens, galaxies is governed by the joint, but conflicting requirements to obtain accurate redshift information and large statistics. We present cosmological results from the full 5000 deg2 of the Dark Energy Survey's first three years of observations (Y3) combining those two-point functions, using for the first time a magnitude-limited lens sample (MAGLIM) of 11 million galaxies, especially selected to optimize such combination, and 100 million background shapes. We consider two flat cosmological models, the Standard Model with dark energy and cold dark matter ( CDM ) a variation with a free parameter for the dark energy equation of state (w CDM ). Both models are marginalized over 25 astrophysical and systematic nuisance parameters. In CDM we obtain for the matter density m=0.320-0.034+0.041 and for the clustering amplitude S88(m/0.3 )0.5=0.778-0.031+0.037 , at 68% C.L. The latter is only 1 smaller than the prediction in this model informed by measurements of the cosmic microwave background by the Planck satellite. In w CDM we find m=0.32-0.046+0.044 , S8=0.777-0.051+0.049 and dark energy equation of state w =-1.031-0.379+0.218 . We find that including smaller scales, while marginalizing over nonlinear galaxy bias, improves the constraining power in the m-S8 plane by 31% and in the m-w plane by 41% while yielding consistent cosmological parameters from those in the linear bias case. These results are combined with those from cosmic shear in a companion paper to present full DES-Y3 constraints from the three two-point functions (3 2 pt ).
  42. Dorn-Wallenstein, T., Levesque, E., Davenport, J., et al., (including Neugent, K.), 2022, ApJ, 940, 27, The Properties of Fast Yellow Pulsating Supergiants: FYPS Point the Way to Missing Red Supergiants
    Fast yellow pulsating supergiants (FYPS) are a recently discovered class of evolved massive pulsators. As candidate supergiant objects, and one of the few classes of pulsating evolved massive stars, these objects have incredible potential to change our understanding of the structure and evolution of massive stars. Here we examine the lightcurves of a sample of 126 cool supergiants in the Magellanic Clouds observed by the Transiting Exoplanet Survey Satellite in order to identify pulsating stars. After making quality cuts and filtering out contaminant objects, we examine the distribution of pulsating stars in the Hertzprung-Russel (HR) diagram, and find that FYPS occupy a region above $\mathrm{log}L/{L}_{\odot }\gtrsim 5.0$ . This luminosity boundary corresponds to stars with initial masses of ~18-20 M , consistent with the most massive red supergiant progenitors of supernovae (SNe) II-P, as well as the observed properties of SNe IIb progenitors. This threshold is in agreement with the picture that FYPS are post-RSG stars. Finally, we characterize the behavior of FYPS pulsations as a function of their location in the HR diagram. We find low-frequency pulsations at higher effective temperatures, and higher-frequency pulsations at lower temperatures, with a transition between the two behaviors at intermediate temperatures. The observed properties of FYPS make them fascinating objects for future theoretical study.
  43. Delrez, L., Murray, C., Pozuelos, F., et al., (including Kunovac, V.), 2022, A&A, 667, A59, Two temperate super-Earths transiting a nearby late-type M dwarf
    Context. In the age of JWST, temperate terrestrial exoplanets transiting nearby late-type M dwarfs provide unique opportunities for characterising their atmospheres, as well as searching for biosignature gases. In this context, the benchmark TRAPPIST-1 planetary system has garnered the interest of a broad scientific community.
    Aims: We report here the discovery and validation of two temperate super-Earths transiting LP 890-9 (TOI-4306, SPECULOOS-2), a relatively low-activity nearby (32 pc) M6V star. The inner planet, LP 890-9 b, was first detected by TESS (and identified as TOI-4306.01) based on four sectors of data. Intensive photometric monitoring of the system with the SPECULOOS Southern Observatory then led to the discovery of a second outer transiting planet, LP 890-9 c (also identified as SPECULOOS-2 c), previously undetected by TESS. The orbital period of this second planet was later confirmed by MuSCAT3 follow-up observations.
    Methods: We first inferred the properties of the host star by analyzing its Lick/Kast optical and IRTF/SpeX near-infrared spectra, as well as its broadband spectral energy distribution, and Gaia parallax. We then derived the properties of the two planets by modelling multi-colour transit photometry from TESS, SPECULOOS-South, MuSCAT3, ExTrA, TRAPPIST-South, and SAINT-EX. Archival imaging, Gemini-South/Zorro high-resolution imaging, and Subaru/IRD radial velocities also support our planetary interpretation.
    Results: With a mass of 0.118 0.002 M, a radius of 0.1556 0.0086 R, and an effective temperature of 2850 75 K, LP 890-9 is the second-coolest star found to host planets, after TRAPPIST-1. The inner planet has an orbital period of 2.73 d, a radius of 1.320 0.027+0.053 R, and receives an incident stellar flux of 4.09 0.12 S. The outer planet has a similar size of 1.367 0.039+0.055R and an orbital period of 8.46 d. With an incident stellar flux of 0.906 0.026 S, it is located within the conservative habitable zone, very close to its inner limit (runaway greenhouse). Although the masses of the two planets remain to be measured, we estimated their potential for atmospheric characterisation via transmission spectroscopy using a mass-radius relationship and found that, after the TRAPPIST-1 planets, LP 890-9 c is the second-most favourable habitable-zone terrestrial planet known so far (assuming for this comparison a similar atmosphere for all planets).
    Conclusions: The discovery of this remarkable system offers another rare opportunity to study temperate terrestrial planets around our smallest and coolest neighbours.

    The photometric and radial velocities data used in this work are only available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr ( or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/667/A59

  44. Johnson, J., Grundy, W., Lemmon, M., et al., 2022, P&SS, 222, 105563, Spectrophotometric properties of materials from the Mars Science Laboratory at Gale crater: 1. Bradbury Landing to Cooperstown
    During the first 443 martian days (sols) of the Mars Science Laboratory (MSL) Curiosity rover mission, visible/near-infrared (445-1012 nm) multispectral observations were acquired at different times of sol by the Mast Camera (Mastcam) and Navigation Camera (Navcam) at five locations along the traverse. Measurements of soil, dust, and rock units spanned sufficient incidence, emission, and phase angles to enable radiative transfer models to constrain the surface scattering functions, single-scattering albedo (w), and microphysical properties of the units at each site. Although the model results were mainly consistent with previous results from other landing sites, there were some notable exceptions. For example, the less dusty "Blue rocks" units were modeled as more backscattering compared to ostensibly dustier "Red rocks" units, which was opposite to results from other landed missions. Relations between the peak phase angle of phase curve ratios, w values, and macroscopic roughness (bar) suggested that unlike most of the materials observed by the Spirit and Opportunity rovers, the effects of particle-scale roughness and internal scattering were a greater influence on MSL units than surface scattering. Also noteworthy were unique photometric signatures modeled from data acquired at the landing site on Sol 20 as part of the first in situ spectrophotometric analyses of materials subjected to erosion and/or surface dust removal from spacecraft descent engines. Modeled w spectra were relatively flat and dark for the Sol 20 Blue rocks unit and were positively correlated with average bar values, similar to some laboratory studies of coarse-grained and/or glassy mafic materials. While low w values and backscattering behaviors were modeled for the Sol 20 "Regolith" unit, the more heavily scoured, lighter-toned regions included soils with extremely forward scattering behaviors, large w values, and that lacked ferric absorption features. The absence of phase reddening effects in all the Sol 20 units likely also was caused by surface disruptions during the landing. Future analyses of additional spectrophotometric data sets from both Curiosity and the Mars 2020 Perseverance rover will continue to yield important comparisons among the variable scattering properties of martian geologic units.
  45. Camacho, H., Andrade-Oliveira, F., Troja, A., et al., (including Kuehn, K.), 2022, MNRAS, 516, 5799, Cosmic shear in harmonic space from the Dark Energy Survey Year 1 Data: compatibility with configuration space results
    We perform a cosmic shear analysis in harmonic space using the first year of data collected by the Dark Energy Survey (DES-Y1). We measure the cosmic weak lensing shear power spectra using the METACALIBRATION catalogue and perform a likelihood analysis within the framework of CosmoSIS. We set scale cuts based on baryonic effects contamination and model redshift and shear calibration uncertainties as well as intrinsic alignments. We adopt as fiducial covariance matrix an analytical computation accounting for the mask geometry in the Gaussian term, including non-Gaussian contributions. A suite of 1200 lognormal simulations is used to validate the harmonic space pipeline and the covariance matrix. We perform a series of stress tests to gauge the robustness of the harmonic space analysis. Finally, we use the DES-Y1 pipeline in configuration space to perform a similar likelihood analysis and compare both results, demonstrating their compatibility in estimating the cosmological parameters S8, 8, and m. We use the DES-Y1 METACALIBRATION shape catalogue, with photometric redshifts estimates in the range of 0.2-1.3, divided in four tomographic bins finding 8(m/0.3)0.5 = 0.766 0.033 at 68 per cent CL. The methods implemented and validated in this paper will allow us to perform a consistent harmonic space analysis in the upcoming DES data.
  46. Athanasopoulos, D., Hanus, J., Avdellidou, C., et al., (including van Belle, G.), 2022, A&A, 666, A116, Asteroid spin-states of a 4 Gyr collisional family
    Context. Families of asteroids generated by the collisional fragmentation of a common parent body have been identified using clustering methods of asteroids in their proper orbital element space. However, there is growing evidence that some of the real families are larger than the corresponding cluster of objects in orbital elements, and there are families that escaped identification by clustering methods. An alternative method has been developed in order to identify collisional families from the correlation between the asteroid fragment sizes and their proper semi-major axis distance from the family centre (V-shape). This method has been shown to be effective in the cases of the very diffuse families that formed billions of years ago.
    Aims: Here we use multiple techniques for observing asteroids to provide corroborating evidence that one of the groups of asteroids identified as a family from the correlation between size and proper semi-major axis of asteroids are real fragments of a common parent body, and thus form a collisional family.
    Methods: We obtained photometric observations of asteroids in order to construct their rotational light curves; we combine them with the literature light curves and sparse-in-time photometry; we input these data in the light curve inversion methods, which allow us to determine a convex approximation to the 3D shape of the asteroids and their orientation in space, from which we extract the latitude (or obliquity) of the spin pole in order to assess whether an object is prograde or retrograde. We included in the analysis spin pole solutions already published in the literature aiming to increase the statistical significance of our results. The ultimate goal is to assess whether we find an excess of retrograde asteroids on the inward side of the V-shape of a 4 Gyr asteroid family identified via the V-shape method. This excess of retrograde rotators is predicted by the theory of asteroid family evolution.
    Results: We obtained the latitude of the spin poles for 55 asteroids claimed to belong to a 4 Gyr collisional family of the inner main belt that consists of low-albedo asteroids. After re-evaluating the albedo and spectroscopic information, we found that nine of these asteroids are interlopers in the 4 Gyr family. Of the 46 remaining asteroids, 31 are found to be retrograde and 15 prograde. We also found that these retrograde rotators have a very low probability (1.29%) of being due to random sampling from an underlying uniform distribution of spin poles.
    Conclusions: Our results constitute corroborating evidence that the asteroids identified as members of a 4 Gyr collisional family have a common origin, thus strengthening their family membership.

    Table B.5 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/666/A116

    This article is dedicated to the memory of Gianfranco Marcon, whose telescopes have contributed to the development of astronomy and to the observations collected for this study.

  47. Naidu, S., Chesley, S., Farnocchia, D., et al., (including Moskovitz, N.), 2022, PSJ, 3, 234, Anticipating the DART Impact: Orbit Estimation of Dimorphos Using a Simplified Model
    We used the times of occultations and eclipses between the components of the 65803 Didymos binary system observed in its light curves from 2003 to 2021 to estimate the orbital parameters of Dimorphos relative to Didymos. We employed a weighted least-squares approach and a modified Keplerian orbit model in order to accommodate the effects from nongravitational forces such as binary YORP that could cause a linear change in mean motion over time. We estimate that the period of the mutual orbit at the epoch 2022 September 26.0 TDB, the day of the DART impact, is 11.921 487 0.000028 hr (1) and that the mean motion of the orbit is changing at a rate of (5.0 1.0) 10-18 rad s-2 (1). The formal 3 uncertainty in orbital phase of Dimorphos during the planned Double Asteroid Redirection Test (DART) mission is 5.4. Observations from 2022 July to September, a few months to days prior to the DART impact, should provide modest improvements to the orbital phase uncertainty and reduce it to about 4.2. These results, generated using a relatively simple model, are consistent with those generated using the more sophisticated model of Scheirich & Pravec, which demonstrates the reliability of our method and adds confidence to these mission-critical results.
  48. Moskovitz, N., Wasserman, L., Burt, B., et al., (including Schottland, R., Bowell, E.), 2022, A&C, 41, 100661, The astorb database at Lowell Observatory
    The astorb database at Lowell Observatory is an actively curated catalog of all known asteroids in the Solar System. astorb has heritage dating back to the 1970s and has been publicly accessible since the 1990s. Work began in 2015 to modernize the underlying database infrastructure, operational software, and associated web applications. That effort involved the expansion of astorb to incorporate new data such as physical properties (e.g. albedo, colors, spectral types) from a variety of sources. The data in astorb are used to support a number of research tools hosted at https://asteroid.lowell.edu. Here we present a full description of the software tools, computational foundation, and data products upon which the astorb ecosystem has been built.
  49. Gatti, M., Jain, B., Chang, C., et al., (including Kuehn, K.), 2022, PhRvD, 106, 083509, Dark Energy Survey Year 3 results: Cosmology with moments of weak lensing mass maps
    We present a cosmological analysis using the second and third moments of the weak lensing mass (convergence) maps from the first three years of data (Y3) data of the Dark Energy Survey. The survey spans an effective area of 4139 square degrees and uses the images of over 100 million galaxies to reconstruct the convergence field. The second moment of the convergence as a function of smoothing scale contains information similar to standard shear 2-point statistics. The third moment, or the skewness, contains additional non-Gaussian information. The data is analyzed in the context of the CDM model, varying five cosmological parameters and 19 nuisance parameters modeling astrophysical and measurement systematics. Our modeling of the observables is completely analytical, and has been tested with simulations in our previous methodology study. We obtain a 1.7% measurement of the amplitude of fluctuations parameter S88(m/0.3 )0.5=0.784 0.013 . The measurements are shown to be internally consistent across redshift bins, angular scales, and between second and third moments. In particular, the measured third moment is consistent with the expectation of gravitational clustering under the CDM model. The addition of the third moment improves the constraints on S8 and m by 15 % and 25 % compared to an analysis that only uses second moments. We compare our results with Planck constraints from the cosmic microwave background, finding a 2.2 - 2.8 tension in the full parameter space, depending on the combination of moments considered. The third moment, independently, is in 2.8 tension with Planck, and thus provides a cross-check on the analyses of 2-point correlations.
  50. Chen, R., Scolnic, D., Rozo, E., et al., (including Kuehn, K.), 2022, ApJ, 938, 62, Measuring Cosmological Parameters with Type Ia Supernovae in redMaGiC Galaxies
    Current and future cosmological analyses with Type Ia supernovae (SNe Ia) face three critical challenges: (i) measuring the redshifts from the SNe or their host galaxies; (ii) classifying the SNe without spectra; and (iii) accounting for correlations between the properties of SNe Ia and their host galaxies. We present here a novel approach that addresses each of these challenges. In the context of the Dark Energy Survey (DES), we analyze an SN Ia sample with host galaxies in the redMaGiC galaxy catalog, a selection of luminous red galaxies. redMaGiC photo-z estimates are expected to be accurate to z/(1+z) ~ 0.02. The DES-5YR photometrically classified SN Ia sample contains approximately 1600 SNe, and 125 of these SNe are in redMaGiC galaxies. We demonstrate that redMaGiC galaxies almost exclusively host SNe Ia, reducing concerns relating to classification uncertainties. With this subsample, we find similar Hubble scatter (to within ~0.01 mag) using photometric redshifts in place of spectroscopic redshifts. With detailed simulations, we show that the bias due to using redMaGiC photo-zs on the measurement of the dark energy equation of state w is up to w ~ 0.01-0.02. With real data, we measure a difference in w when using the redMaGiC photo-zs versus the spec-zs of w = 0.005. Finally, we discuss how SNe in redMaGiC galaxies appear to comprise a more standardizable population, due to a weaker relation between color and luminosity () compared to the DES-3YR population by ~5. These results establish the feasibility of performing redMaGiC SN cosmology with photometric survey data in the absence of spectroscopic data.
  51. Sheppard, S., Tholen, D., Pokorny, P., et al., (including Thirouin, A.), 2022, AJ, 164, 168, A Deep and Wide Twilight Survey for Asteroids Interior to Earth and Venus
    We are conducting a survey using twilight time on the Dark Energy Camera with the Blanco 4 m telescope in Chile to look for objects interior to Earth's and Venus' orbits. To date we have discovered two rare Atira/Apohele asteroids, 2021 LJ4 and 2021 PH27, which have orbits completely interior to Earth's orbit. We also discovered one new Apollo-type Near Earth Object (NEO) that crosses Earth's orbit, 2022 AP7. Two of the discoveries have diameters 1 km. 2022 AP7 is likely the largest Potentially Hazardous Asteroid (PHA) discovered in about eight years. To date we have covered 624 square degrees of sky near to and interior to the orbit of Venus. The average images go to 21.3 mag in the r band, with the best images near 22nd mag. Our new discovery 2021 PH27 has the smallest semimajor axis known for an asteroid, 0.4617 au, and the largest general relativistic effects (53 arcsec/century) known for any body in the solar system. The survey has detected ~15% of all known Atira NEOs. We put strong constraints on any stable population of Venus co-orbital resonance objects existing, as well as the Atira and Vatira asteroid classes. These interior asteroid populations are important to complete the census of asteroids near Earth, including some of the most likely Earth impactors that cannot easily be discovered in other surveys. Comparing the actual population of asteroids found interior to Earth and Venus with those predicted to exist by extrapolating from the known population exterior to Earth is important to better understand the origin, composition, and structure of the NEO population.
  52. Burke, C., Liu, X., Shen, Y., et al., (including Kuehn, K.), 2022, MNRAS, 516, 2736, Dwarf AGNs from Optical Variability for the Origins of Seeds (DAVOS): insights from the dark energy survey deep fields
    We present a sample of 706, z < 1.5 active galactic nuclei (AGNs) selected from optical photometric variability in three of the Dark Energy Survey (DES) deep fields (E2, C3, and X3) over an area of 4.64 deg2. We construct light curves using difference imaging aperture photometry for resolved sources and non-difference imaging PSF photometry for unresolved sources, respectively, and characterize the variability significance. Our DES light curves have a mean cadence of 7 d, a 6-yr baseline, and a single-epoch imaging depth of up to g ~ 24.5. Using spectral energy distribution (SED) fitting, we find 26 out of total 706 variable galaxies are consistent with dwarf galaxies with a reliable stellar mass estimate ($M_{\ast }\lt 10^{9.5}\, {\rm M}_\odot$; median photometric redshift of 0.9). We were able to constrain rapid characteristic variability time-scales (~ weeks) using the DES light curves in 15 dwarf AGN candidates (a subset of our variable AGN candidates) at a median photometric redshift of 0.4. This rapid variability is consistent with their low black hole (BH) masses. We confirm the low-mass AGN nature of one source with a high S/N optical spectrum. We publish our catalogue, optical light curves, and supplementary data, such as X-ray properties and optical spectra, when available. We measure a variable AGN fraction versus stellar mass and compare to results from a forward model. This work demonstrates the feasibility of optical variability to identify AGNs with lower BH masses in deep fields, which may be more 'pristine' analogues of supermassive BH seeds.
  53. Doyle, L., Cegla, H., Bryant, E., et al., (including Kunovac, V.), 2022, MNRAS, 516, 298, The Hot Neptune WASP-166 b with ESPRESSO - I. Refining the planetary architecture and stellar variability
    In this paper, we present high-resolution spectroscopic transit observations from ESPRESSO of the super-Neptune WASP-166 b. In addition to spectroscopic ESPRESSO data, we analyse photometric data from TESS of six WASP-166 b transits along with simultaneous NGTS observations of the ESPRESSO runs. These observations were used to fit for the planetary parameters as well as assessing the level of stellar activity (e.g. spot crossings, flares) present during the ESPRESSO observations. We utilize the reloaded Rossiter McLaughlin (RRM) technique to spatially resolve the stellar surface, characterizing the centre-to-limb convection-induced variations, and to refine the star-planet obliquity. We find WASP-166 b has a projected obliquity of $\lambda = -15.52^{+2.85}_{-2.76}\, ^{\circ }$ and vsin (i) = 4.97 0.09 km s-1 which is consistent with the literature. We were able to characterize centre-to-limb convective variations as a result of granulation on the surface of the star on the order of a few km s-1 for the first time. We modelled the centre-to-limb convective variations using a linear, quadratic, and cubic model with the cubic being preferred. In addition, by modelling the differential rotation and centre-to-limb convective variations simultaneously, we were able to retrieve a potential antisolar differential rotational shear ( ~ -0.5) and stellar inclination (i* either 42.03$^{+9.13}_{-9.60}\, ^{\circ }$ or 133.64$^{+8.42}_{-7.98}\, ^{\circ }$ if the star is pointing towards or away from us). Finally, we investigate how the shape of the cross-correlation functions change as a function of limb angle and compare our results to magnetohydrodynamic simulations.
  54. Marsset, M., DeMeo, F., Burt, B., et al., (including Moskovitz, N.), 2022, EPSC, EPSC2022-287, The debiased compositional distribution of Near-Earth Objects
    We report 491 new near-infrared spectroscopic measurements of 420 Near-Earth Objects (NEOs) collected on NASA's IRTF in the context of MITHNEOS (PI: DeMeo). The measurements were combined with previously published data (Binzel et al. 2019) and bias-corrected for albedo variations to derive the intrinsic compositional distribution of the overall NEO population. We also investigated individual subpopulations coming from various escape routes (ERs) in the asteroid belt by use of the dynamical model of Granvik et al. (2018). The resulting distributions reflect well the compositional gradient of the asteroid belt, with decreasing fractions of silicate-rich (S- and Q-type) bodies and increasing fractions of carbonaceous (B-, C-, D- and P-type) bodies as a function of increasing ER distance from the Sun. The compositional match between NEOs and their predicted source populations validates dynamical models used to identify ERs and argues against strong composition change in the main belt between approximately 5 km and 100 m. An exception comes from the overabundance of D-type NEOs from the 5:2J and, to a lesser extent, the 3:1J and 6 ERs, hinting at the presence of a large population of small D-type asteroids in the main belt. Alternatively, this excess may indicate spectral evolution from D-type surfaces to C and P types due to space weathering or point to preferential fragmentation of D-types in the NEO space. No further evidence for the existence of collisional families in the main belt, below the detection limit of current main-belt surveys, was found in this work.
  55. Oszkiewicz, D., Troianskyi, V., Wilawer, E., et al., (including Skiff, B., Polakis, T., Moskovitz, N.), 2022, EPSC, EPSC2022-340, Spins and shapes of V-type asteroids outside the dynamical Vesta family
    Vast majority of known V-type asteroids belong to the dynamical Vesta family. A small number of V-types in the mid and outer parts of the Main Asteroid Belt is considered unrelated to the fossil planetesimal (4) Vesta. These objects have low probability of dynamically evolving from the Vesta family and show spectral properties distinct from typical Vestoids [1-7]. Whether there are V-types unrelated to Vesta (non-Vestoids) in the inner part of the Main Asteroid Belt is still an open question. To answer it, we performed a large and long-lasting observing campaign of V-types in the inner Main Belt outside the dynamical Vesta family [8,9]. We determine their rotational properties and compare them with the numerical simulations made by Nesvorny et al. 2008. According to that study 81% of objects evolving from the Vesta family to so-called Cell I (defined by orbital elements 2.2 au<a<2.3 au, 0.05<e<0.2, 0 deg <i<10 deg) and 40% to Cell II (2.32 au <a<2.48 au, 0.05<e<0.2, 2 deg<i< 6 deg) should have retrograde rotations. We observed a total of 23 asteroids larger than 5 km in diameter in both of those Cells over multiple apparitions. We determined spins and shapes for 13 of them so far. In Cell I we found only retrograde objects and in Cell II 6 prograde and 2 retrograde objects. With the complete sample we plan to put constraints on the distribution of possible non-Vestoids in the inner Main Belt.[1] Lazzaro, D. et al., 2000, Science 288, 2033-2035.[2] Hardersen et al., 2004, 167, Icarus 170-177[3] Michtchenko et al., 2002, Icarus 158, 343-359.[4] Fulvio, D. et al, 2018, Planetary and Space Science 164, 37-43.[5] Ieva, et al. 2016, Monthly Notices of the Royal Astronomical Society 455, 2871-2888.[6] Ieva, S.et al., 2018, Monthly Notices of the Royal Astronomical Society 479, 2607-2614.[7] Roig, F. et al. 2008, Icarus 194, 125-136.[8] Oszkiewicz, D., et al., 2020, Astronomy & Astrophysics 643, A117[9] Oszkiewicz, D. et al., 2021, Icarus 357, 114158.[10] Nesvorny, D., et al., 2008, Icarus 193, 85-95.
  56. Avdellidou, C., Delbo, M., Morbidelli, A., et al., (including van Belle, G.), 2022, EPSC, EPSC2022-422, On the discovery of the main belt source of the enstatite chondrites.
    Introduction: Linking a meteorite type to a specific parent asteroid allows us to gain insight into the composition of the latter as well as the time, and indirectly the heliocentric distance of its formation. Up to now there have been established solid links between the HEDs and the inner main belt asteroid family of (4) Vesta [1] as well as between the ordinary chondrites and asteroids belonging to the so-called spectroscopic S-complex [2]. Here we report on our search for the enstatite chondrites parent body. We base our analysis on two facts: that (i) inner main belt asteroid collisional families are the most favoured to deliver meteorites to Earth, and (ii) enstatite chondrites (divided in EH and EL groups) have reflectance spectra that are within the broad asteroid spectroscopic X-complex [3]. The newly discovered asteroid families of Athor and Zita [4] are the only two families of the inner main belt that belong to the spectroscopic X-complex and thus are promising candidates. Methods and Results: In order to investigate the potential link between the enstatite chondrite meteorites and the aforementioned X-complex asteroid families, we performed near-infrared observations of a statistically significant number of members of Athor and Zita. These were combined with the visible data from the literature and finally each asteroid spectrum was classified using the most common asteroid spectral taxonomy. We showed that the Athor and Zita families are spectroscopically distinct from each other and homogenous among their respective members. Moreover, both families have distinct geometric albedo values, with Athor family being brighter. Focusing on the Athor family, we performed curve matching and absolute reflectance comparison with all the available laboratory meteorite spectra in NASA Reflectance Experiment Laboratory and Planetary Spectrophotometer Facility databases. We will report on our matching and provide a number of further evidence that inner main belt families could indeed deliver enstatite chondrites to Earth. Acknowledgments: We acknowledge support from the ANR ORIGINS (ANR-18-CE31-13-0014). CA was supported by the project "Investissements d'Avenir" UCA-JEDI (ANR-15-IDEX-01) and the European Space Agency, AM acknowledges support from the ERC advanced grant HolyEarth N. 101019380. KJW acknowledges support from the Project ESPRESSO, a NASA SSERVI program at SwRI. This work is based on data provided by the Minor Planet Physical Properties Catalogue (MP3C, mp3c.oca.eu) of the Observatoire de la Cote d'Azur. This research utilises spectra acquired at the NASA RELAB facility at Brown University and at Planetary Spectrophotometer Facility (PSF) at University of Winnipeg.References: [1] Russell C.T. et al. 2012, Science 336, 6082, 684.[2] Reddy V. et al. 2015, Asteroids IV, University of Arizona Press, Tucson, 895, 43-63[3] Vernazza P. et al. 2009. Icarus 202, 2, 477-486.[4] Delbo M. et al. 2019. Astronomy & Astrophysics 624, A69.
  57. Bourdelle de Micas, J., Fornasier, S., Delbo, M., et al., (including Van Belle, G.), 2022, EPSC, EPSC2022-440, Composition of Inner Main Belt Planetesimals
    Asteroids, along with other small bodies, are what is left over of the original planetesimal disk from the planet-formation era. Therefore, these objects are considered the best tracers for the processes that occurred during the earliest history of our Solar System. However, the majority of asteroids are fragments generated by the collisional breakup of the planetesimals, the first ~100-km sized bodies (Morbidelli et al., 2008, Delbo' et al., 2019) that accreted in the protoplanetary disk of our Sun. Nevertheless, a small fraction of the planetesimal population survived the collisional evolution. In order to study these objects, the first step is to identify these surviving planetesimals among all the other (fragment) asteroids. To do so, we "cleaned" the inner part of the asteroid main belt (2,1 < a < 2,5) from all asteroid collisional family members (using the method of Bolin et al., 2017, Delbo' et al., 2017, 2019), thus revealing those asteroids that are not fragments that formed in the main belt. Thanks to this method, we revealed 64 surviving planetesimals in the inner main belt.We carried out a spectroscopic survey of these identified IMB planetesimals, in order to constrain their composition and mineralogy. In particular, we performed visible and near-infrared spectroscopy using several telescopes such as the 1.82m Copernico Telescopio (Asiago, Italy) for the visible spectroscopy and the 4.2 Lowell Discovery Telescope (Flagstaff, USA); the 3.2 NASA Infrared Telescope Facility (Hawaii, USA) and the Telescopio Nazionale Galileo (La Palma, Spain) for the near-infrared part. To complete our survey, we also used spectra in the visible and near-infrared published in the literature, as well as size and albedo information that we obtained from the Minor Planet Physical Properties Catalog (https://mp3c.oca.eu/). We performed the taxonomic classification following the Bus-DeMeo taxonomy (Bus et al., 2002; DeMeo et al., 2009), and using the M4AST tool (http://m4ast.imcce.fr) (Popescu et al., 2012). A visual inspection to identify the presence of absorption bands characteristic of some classes was performed to check the robustness of the automatic taxonomic classification. In addition, we compute for each planetesimal several spectral parameters, such as spectral slopes, and center, depth and area of absorption bands, when these are present. We also performed calculation of their mass, based on the method of (Carry, 2012). Finally, we used the RELAB database (Pieters, 1983), to look for meteorite analogues of each planetesimal. We found that planetesimals of the Inner Main Belt (IMB) belong mainly to the S-complex (~45%), followed by C-complex (~25%) and X-complex (~17%). Further investigations on S-complex planetesimals showed that, for a majority of them, they are best matched by spectra of ordinary chondrites meteorites. We did not find any correlation with diameters, semimajor axis and the ratio of olivine/pyroxene. Almost 60% of the C-complex planetesimals belong to the Ch/Cgh types, showing spectroscopic features associated with hydrated minerals, and consequently indicating the presence of liquid water in the early formation phases of these objects. We also found that almost 5% of the IMB planetesimals belong to the D/T types with a diameter greater than 25 km. As this taxonomical class, as well as Ch/Cgh types, are likely to have formed in the outer part of the Solar System (at 3-7 au), their presence in the IMB (2,1-2,5 au) can be explained by dynamical models invoking large semimajor axis migration of these objects (e.g., Grand Tack of Walsh et al., 2011; low-mass asteroid belt of Raymond and Izidoro, 2017b for the C-complex and Vokrouhlicky et al., 2016 for the D/T types).Here, we will present the spectroscopic, physical and compositional results of our IMB planetesimals survey as well as the implications for planetary formation models.Acknowledgements: We acknowledge support from the ANR ORIGINS (ANR-18-CE31-13-0014).References : Morbidelli A. et al, Physica Scripta, Volume 130, Issue, id 014028 (2008) ; Delbo M. et al., A&A, Volume 624, id. A69 (2019) ; Bolin B. T. et al., Icarus, Volume 282, 2017, Pages 290-312 ; Delbo M. et al., Science, Volume 357, Issue 6355, pages 1026-1029, (2017) ; Bus S. J. et al., Icarus, Volume 158, Issue 1, Pages 146-177 (2002) ; DeMeo F. E. et al., Icarus, Volume 202, Issue 1, Pages 160-180 (2009); Carry, B. Planetary and Space Science, Volume 73, Issue 1, p. 98-118. (2012) ; Popescu M. et al., A&A, Volume 544, id. A130 (2012) ; Pieters, C. M., J. Geophys. Res., Volume 88, pages 9534- 9544 (1983) ; Walsh K. J. et al., Nature, Volume 475, Issue 7355, Pages 206-209 (2011) ; Raymond S. N. et al., Science Advances, Volume 3, Issue 9, Pages e1701138 (2017) ; Vokrouhlicky D. et al., The Astronomical Journal, Volume 152, Issue 2, id. 39 (2016).
  58. Athanasopoulos, D., Hanus, J., Avdellidou, C., et al., (including Van Belle, G.), 2022, EPSC, EPSC2022-949, Asteroid spin-states of a 4 Gyr-old collisional family.
    IntroductionAsteroid families generated by the collisional fragmentation of a common parent body have been identified using clustering methods of asteroids in their proper orbital element space (Broz & Morbidelli 2013; Tsirvoulis et al. 2018; Dermott et al. 2021). However, there is growing evidence that some of the real families are larger than the corresponding cluster of objects in orbital elements, as well as there are families that escaped identification from clustering methods (Milani et al. 2014). An alternative method has been developed by Bolin et al. (2017); Delbo et al. (2017), in order to identify collisional families from the correlation between the asteroid fragment sizes and their proper semimajor axis distance from the family center (V-shape). This method has been shown to be effective in the cases of the very diffused families that have formed Gyrs ago. Based on this method, a 4 Gyr-old (so-called primordial) collisional family of the inner main belt has been identified consisting of low-albedo asteroids (Delbo et al. 2017). The theory of asteroid family evolution predicts that there is an excess on retrograde asteroids in the inward side of the family's V-shape. For this reason, photometric observations were performed in order to construct their rotational light curves and determine their shape and spin state. Dataset and ObservationsWe combined data of asteroid lightcurves that we collected from the databases, sparse photometric data obtained from different surveys and existing shape models. Aiming to enlarge our input dataset used for the shape modelling, which would potentially lead to new and improved shape solutions, we performed additional ground-based photometric observations.An international observing campaign has been initiated in the framework of our international initiative called Ancient Asteroids[1], aiming to collect dense photometric data for asteroids that belong to the oldest asteroid families (Athanasopoulos et al. 2021). MethodThe photometric datasets include both dense photometric data from ground-based facilities, as well as sparse data from several sky surveys and space missions. Appropriate analysis techniques were used for each type of dataset to extract the asteroid's rotational light curve and use the convex inversion (CI) method developed by Kaasalainen & Torppa (2021); Kaasalainen et al. (2021). So far, the CI has been used to derive asteroid models for more than 3,460 asteroids that are stored in the DAMIT database. ResultsThe spin state for 54 family members was determined by additionally using literature and sparse photometric data from ground and space observatories. Moreover, we measured rotation periods for 8 asteroids for the first time.Combining new and literature data, we determined shapes and spin states for 54 asteroids that belong to the nominal population of the primordial family. This corresponds to 50% of the population in the sliver between the left-wing border of the Polana and the primordial family (see Fig. 1). Specifically, we calculated 23 new complete asteroid models, 16 revised and 8 new partial models, where 32 asteroids have retrograde rotation and 22 prograde.Based on our analysis, we indicated 9 interlopers in the sample of 54 studied objects. From these 45 confirmed asteroid family members, 29 asteroids (65%) models have retrograde rotation and 16 prograde, including also the partial solutions. Fig. 1: Panel A: The primordial family members are presented in proper semi-major axis vs. inverse diameter plane, along with the low albedo asteroids. Yellow diamond markers present members with known spin pole from the literature. Moreover, "plus", cross and square markers show the sources of dense lightcurves for these members. Panel B: The left side of the V-shape of the primordial family, where the red markers show the retrograde and blue markers the retrograde asteroids respectively. ConclusionWe carried out a campaign of photometric observations of those asteroids that have been claimed to be members of one of the oldest collisional (primordial) families in the Solar System and we extract the lightcurves, spin state and shape for 45 members.The statistical predominance of the retrograde spin poles is due to a physical process, as it was claimed by Delbo et al. 2017, namely formation as collisional fragments of a common parent body, a subsequent dynamical evolution driven by the Yarkovsky effect. The results of this research constitute corroborating evidence that the asteroids as members of a 4 Gry-old collisional family have a common origin, thus strengthening their family membership. AcknowledgmentsMD and CA acknowledge support from ANR "ORIGINS" (ANR-18-CE31-0014). This work is based on data provided by the Minor Planet Physical Properties Catalogue (MP3C) of the Observatoire de la Cote d'Azur. The research of JH has been supported by the Czech Science Foundation through grant 20-08218S. The work of OP has been supported by INTER-EXCELLENCE grant LTAUSA18093 from the Ministry of Education, Youth, and Sports. Support for T.W.-S.H. was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51458.001-A awarded by the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555.We thank the Las Cumbres Observatory and their staff for its continuing support of the ASAS-SN project, supported by the Gordon and Betty Moore Foundation through grant GBMF5490 to the Ohio State University and funded in part by the Alfred P. Sloan Foundation grant G-2021-14192 and NSF grant AST-1908570. Development of ASAS-SN has been supported by NSF grant AST-0908816, the Mt. Cuba Astronomical Foundation, the Center for Cosmology and AstroParticle Physics at the Ohio State University, the Chinese Academy of Sciences South America Center for Astronomy (CAS-SACA), the Villum Foundation, and George Skestos. ReferencesAthanasopoulos, D. et al. 2021, in European Planetary Science Congress Vol. 15, EPSC2021-335Bolin, B. T. et al. 2017, Icarus, 282, 290Broz, M. & Morbidelli, A. 2013, Icarus, 223, 844Delbo', M. et al. 2017, Science, 357, 1026Dermott, S. F. et al. 2021, MNRAS, 505, 1917Kaasalainen, M. & Torppa, J. 2001, Icarus, 153, 24Kaasalainen, M. et al. 2001, Icarus, 153, 37Milani, A. et al. 2014, Icarus, 239, 46Tsirvoulis, G. et al. 2018, Icarus, 304, 14 [1] http://users.uoa.gr/~kgaze/ancient_asteroids.html Acknowledgment: DA wishes to thank the Hellenic Astronomical Society (Hel.A.S.) for a travel grant.
  59. Bendjoya, P., Cellino, A., Rivet, J., et al., (including Devogele, M.), 2022, A&A, 665, A66, The Calern Asteroid Polarisation Survey. An updated catalogue of asteroid polarimetric data
    Context. The Calern Asteroid Polarimetric Survey (CAPS), a collaboration between the INAF Astrophysical Observatory of Torino (Italy) and the Observatoire de la Cote d'Azur (Nice, France), has produced new asteroid polarimetric data for a number of years, and is one of the most important, currently active projects of asteroid polarimetry.
    Aims: The purpose of this paper is to make public the CAPS data collected thus far, to explain the adopted techniques of data reduction and computation of phase-polarisation curves for the measured objects, and explain, by means of some examples, the importance of the CAPS database.
    Methods: The pipeline of data reduction has been recently updated and made as automatic as possible, using numerical algorithms developed specifically for the purposes of CAPS. The derivation of phase-polarisation curves for the observed asteroids is done using established criteria and algorithms that have recently been slightly improved, and are also summarised in this paper.
    Results: The CAPS catalogue is a steadily growing source of information which can be exploited for different purposes, including, but not limited to, an updated calibration of the relations existing between different polarimetric parameters and the geometric albedo of the objects, and a study of classes of objects that can be most easily identified by means of their polarimetric properties. These subjects will be more specifically discussed in separate papers.
    Conclusions: Asteroid polarimetry data nicely complement the results of other more commonly used techniques, including visible and IR photometry and spectroscopy. CAPS contains a lot of much-desired information about physical properties, which can hardly be inferred by means of other techniques.

    Full Tables A.1 and A.2 are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/665/A66

  60. Bourdelle de Micas, J., Fornasier, S., Avdellidou, C., et al., (including van Belle, G., Grundy, W., Moskovitz, N.), 2022, A&A, 665, A83, Composition of inner main-belt planetesimals

    Aims: We carried out a spectroscopic survey in order to investigate the composition of 64 asteroids of the inner main belt, which are leftovers of the original planetesimals of our Solar System (we call them inner main belt planetesimals or IMBPs). Following published methods, we identified IMBPs in the inverse size versus semimajor axis () space, after the removal of all asteroids belonging to collisional families.
    Methods: We conducted several ground-based observational campaigns of these IMBPs in the visible range at the 1.82 m Asiago telescope, and in the near-infrared range at the Telescopio Nationale Galileo, the Lowell Discovery Telescope, and the NASA InfraRed Telescope Facility telescopes. As several of the identified planetesimals already have spectra published in the literature, we collected all the available data and focused the telescope time to investigate those never observed before, or to complete the 0.45-2.5 m range spectrum for those for which there is only partial spectral coverage or data with poor signal-to-noise ratio. In this way, we obtained new spectra for 24 IMBPs. Combining new and literature observations, we present spectra for 60 IMBPs in both the visible and near-infrared range, and 4 IMBPs in the visible only. All spectra were classified following well-established taxonomies. We also characterized their spectral absorption bands - when present -, their spectral slopes, and their mineralogy. In addition, we performed curve matching between astronomical and laboratory spectra in order to identify the closest meteorite analog using the RELAB database.
    Results: The majority of the IMBPs belong to the S-complex; the latter are best matched with ordinary chondrite meteorites, and their olivine/(olivine and pyroxene) abundance ratio is not correlated with the semi-major axis. This result does not support the hypothesis that this ratio increases with heliocentric distance. Furthermore, ~27% of the IMBPs belong to the C-complex, where Ch/Cgh types dominate, meaning that most of the carbonaceous-rich planetesimals were aqueously altered. These are best fitted by CM2 carbonaceous chondrite meteorites. Finally, the remaining IMBPs (~20%) belong to the X-complex, and have various mineralogies and meteorite matches, while a few are end-member classes, including L-, K-, V-, and D- or T-types.
    Conclusions: Our spectroscopic investigation of IMBPs confirms that silicate-rich bodies dominated the inner main belt where temperature has permitted the condensation of silicate rocks. However, almost all the spectral types are found, with the notable exception of olivine-rich A-types and Q-type asteroids. Their absence, as well as the absence of the R- and O-types among planetesimals, might be due to the rarity of these types among large asteroids. However, the absence of Q-types among primordial planetesimals is expected, as they have undergone surface rejuvenating processes. Therefore, Q-types have relatively young and less weathered surfaces compared to other types. Our results support the hypothesis of compositional mixing in the early Solar System. In particular, the fact that most of the C-complex planetesimals are aqueous altered, and the presence of three D- or T-type asteroids among them indicate that these bodies migrated from beyond 3 au to their current position.
  61. Caballero, J., Gonzalez-Alvarez, E., Brady, M., et al., (including von Braun, K.), 2022, A&A, 665, A120, A detailed analysis of the Gl 486 planetary system
    Context. The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5 V star at just 8 pc with a warm transiting rocky planet of about 1.3 R and 3.0 M. It is ideal for both transmission and emission spectroscopy and for testing interior models of telluric planets.
    Aims: To prepare for future studies, we aim to thoroughly characterise the planetary system with new accurate and precise data collected with state-of-the-art photometers from space and spectrometers and interferometers from the ground.
    Methods: We collected light curves of seven new transits observed with the CHEOPS space mission and new radial velocities obtained with MAROON-X at the 8.1 m Gemini North telescope and CARMENES at the 3.5 m Calar Alto telescope, together with previously published spectroscopic and photometric data from the two spectrographs and TESS. We also performed near-infrared interferometric observations with the CHARA Array and new photometric monitoring with a suite of smaller telescopes (AstroLAB, LCOGT, OSN, TJO). This extraordinary and rich data set was the input for our comprehensive analysis.
    Results: From interferometry, we measure a limb-darkened disc angular size of the star Gl 486 at LDD = 0.390 0.018 mas. Together with a corrected Gaia EDR3 parallax, we obtain a stellar radius R* = 0.339 0.015 R. We also measure a stellar rotation period at Prot = 49.9 5.5 days, an upper limit to its XUV (5-920 A) flux informed by new Hubble/STIS data, and, for the first time, a variety of element abundances (Fe, Mg, Si, V, Sr, Zr, Rb) and C/O ratio. Moreover, we imposed restrictive constraints on the presence of additional components, either stellar or sub-stellar, in the system. With the input stellar parameters and the radial-velocity and transit data, we determine the radius and mass of the planet Gl 486 b at Rp = 1.3430.062+0.063 R and Mp = 3.000.12+0.13 M, with relative uncertainties of the planet radius and mass of 4.7% and 4.2%, respectively. From the planet parameters and the stellar element abundances, we infer the most probable models of planet internal structure and composition, which are consistent with a relatively small metallic core with respect to the Earth, a deep silicate mantle, and a thin volatile upper layer. With all these ingredients, we outline prospects for Gl 486 b atmospheric studies, especially with forthcoming James Webb Space Telescope (Webb) observations.
  62. Avdellidou, C., Delbo, M., Morbidelli, A., et al., (including van Belle, G.), 2022, A&A, 665, L9, Athor asteroid family as the source of the EL enstatite meteorites
    The identification of meteorite parent bodies provides the context for understanding planetesimal formation and evolution as well as the key Solar System events they have witnessed. However, identifying such links has proven challenging and some appear ambiguous. Here, we identify that the family of asteroid fragments whose largest member is (161) Athor is the unique source of the rare EL enstatite chondrite meteorites, the closest meteorites to Earth in terms of their isotopic ratios. The Athor family was created by the collisional fragmentation of a parent body 3 Gyr ago in the inner main belt. We calculate that the diameter of the Athor family progenitor was 64 km in diameter, much smaller than the putative size of the EL original planetesimal. Therefore, we deduce that the EL planetesimal that accreted in the terrestrial planet region underwent a first catastrophic collision in that region, and one of its fragments suffered a more recent catastrophic collision in the main belt, generating the current source of the EL meteorites.
  63. Pang, X., Li, Y., Tang, S., et al., 2022, ApJL, 937, L7, Dynamical Origin for the Collinder 132-Gulliver 21 Stream: A Mixture of Three Comoving Populations with an Age Difference of 250 Myr
    We use Gaia DR3 data to study the Collinder 132-Gulliver 21 region via the machine-learning algorithm STARGO and find eight subgroups of stars (ASCC 32, Collinder 132 gp 1-6, Gulliver 21) located in close proximity. Three comoving populations were identified among these eight subgroups: (i) a coeval 25 Myr old moving group (Collinder 132), (ii) an intermediate-age (50-100 Myr) group, and (iii) the 275 Myr old dissolving cluster Gulliver 21. These three populations form parallel diagonal stripe-shape overdensities in the U-V distribution, which differ from open clusters and stellar groups in the solar neighborhood. We name this kinematic structure the Collinder 132-Gulliver 21 stream, as it extends over 270 pc in the 3D space. The oldest population, Gulliver 21, is spatially surrounded by the Collinder 132 moving group and the intermediate-age group. Stars in the Collinder 132-Gulliver 21 stream have an age difference up to 250 Myr. Metallicity information shows a variation of 0.3 dex between the youngest and oldest populations. The formation of the Collinder 132-Gulliver 21 stream involves both star formation and dynamical heating. The youngest population (Collinder 132 moving group) with homogeneous metallicity is probably formed through filamentary star formation. The intermediate-age and oldest populations were then scattered by the Galactic bar or spiral structure resonance to intercept Collinder 132's orbit. Without mutual interaction between each population, the three populations are flying by each other currently and will become three distinct groups again in ~50 Myr.
  64. Loyd, R., Mason, J., Jin, M., et al., (including Llama, J., Richey-Yowell, T.), 2022, ApJ, 936, 170, Constraining the Physical Properties of Stellar Coronal Mass Ejections with Coronal Dimming: Application to Far-ultraviolet Data of Eridani
    Coronal mass ejections (CMEs) are a prominent contributor to solar system space weather and might have impacted the Sun's early angular momentum evolution. A signal diagnostic of CMEs on the Sun is coronal dimming: a drop in coronal emission, tied to the mass of the CME, that is the direct result of removing emitting plasma from the corona. We present the results of a coronal dimming analysis of Fe XII 1349 A and Fe XXI 1354 A emission from Eridani ( Eri), a young K2 dwarf, with archival far-ultraviolet observations by the Hubble Space Telescope's Cosmic Origins Spectrograph. Following a flare in 2015 February, Eri's Fe XXI emission declined by 81 5%. Although enticing, a scant 3.8 minutes of preflare observations allows for the possibility that the Fe XXI decline was the decay of an earlier, unseen flare. Dimming nondetections following each of three prominent flares constrain the possible mass of ejected Fe XII-emitting (1 MK) plasma to less than a few 1015 g. This implies that CMEs ejecting this much or more 1 MK plasma occur less than a few times per day on Eri. On the Sun, 1015 g CMEs occur once every few days. For Eri, the mass-loss rate due to CME-ejected 1 MK plasma could be < 0.6 ${\dot{M}}_{\odot }$ , well below the star's estimated 30 ${\dot{M}}_{\odot }$ mass-loss rate (wind + CMEs). The order-of-magnitude formalism we developed for these mass estimates can be broadly applied to coronal dimming observations of any star.
  65. Kovacs, A., Vielzeuf, P., Ferrero, I., et al., (including Kuehn, K.), 2022, MNRAS, 515, 4417, Dark Energy Survey Year 3 results: Imprints of cosmic voids and superclusters in the Planck CMB lensing map
    The CMB lensing signal from cosmic voids and superclusters probes the growth of structure in the low-redshift cosmic web. In this analysis, we cross-correlated the Planck CMB lensing map with voids detected in the Dark Energy Survey Year 3 (Y3) data set (~5000 deg2), expanding on previous measurements that used Y1 catalogues (~1300 deg2). Given the increased statistical power compared to Y1 data, we report a 6.6 detection of negative CMB convergence () imprints using approximately 3600 voids detected from a redMaGiC luminous red galaxy sample. However, the measured signal is lower than expected from the MICE N-body simulation that is based on the CDM model (parameters m = 0.25, 8 = 0.8), and the discrepancy is associated mostly with the void centre region. Considering the full void lensing profile, we fit an amplitude $A_{\kappa }=\kappa _{{\rm DES}}/\kappa _{{\rm MICE}}$ to a simulation-based template with fixed shape and found a moderate 2 deviation in the signal with A 0.79 0.12. We also examined the WebSky simulation that is based on a Planck 2018 CDM cosmology, but the results were even less consistent given the slightly higher matter density fluctuations than in MICE. We then identified superclusters in the DES and the MICE catalogues, and detected their imprints at the 8.4 level; again with a lower-than-expected A = 0.84 0.10 amplitude. The combination of voids and superclusters yields a 10.3 detection with an A = 0.82 0.08 constraint on the CMB lensing amplitude, thus the overall signal is 2.3 weaker than expected from MICE.
  66. Doux, C., Jain, B., Zeurcher, D., et al., (including Kuehn, K.), 2022, MNRAS, 515, 1942, Dark energy survey year 3 results: cosmological constraints from the analysis of cosmic shear in harmonic space
    We present cosmological constraints from the analysis of angular power spectra of cosmic shear maps based on data from the first three years of observations by the Dark Energy Survey (DES Y3). Our measurements are based on the pseudo-C method and complement the analysis of the two-point correlation functions in real space, as the two estimators are known to compress and select Gaussian information in different ways, due to scale cuts. They may also be differently affected by systematic effects and theoretical uncertainties, making this analysis an important cross-check. Using the same fiducial Lambda cold dark matter model as in the DES Y3 real-space analysis, we find ${S_8 \equiv \sigma _8 \sqrt{\Omega _{\rm m}/0.3} = 0.793^{+0.038}_{-0.025}}$, which further improves to S8 = 0.784 0.026 when including shear ratios. This result is within expected statistical fluctuations from the real-space constraint, and in agreement with DES Y3 analyses of non-Gaussian statistics, but favours a slightly higher value of S8, which reduces the tension with the Planck 2018 constraints from 2.3 in the real space analysis to 1.5 here. We explore less conservative intrinsic alignments models than the one adopted in our fiducial analysis, finding no clear preference for a more complex model. We also include small scales, using an increased Fourier mode cut-off up to $k_{\rm max}={5}\, {h}\, {\rm Mpc}^{-1}$, which allows to constrain baryonic feedback while leaving cosmological constraints essentially unchanged. Finally, we present an approximate reconstruction of the linear matter power spectrum at present time, found to be about 20 per cent lower than predicted by Planck 2018, as reflected by the lower S8 value.
  67. Levine, S., Ellsworth-Bowers, T., Bida, T., et al., (including Hamilton, R., Kuehn, K.), 2022, SPIE, 12182, 1218227, Status of the Lowell Discovery Telescope (LDT) and assessment of the image quality at the focal plane
    The Lowell Discovery Telescope (LDT, formerly known as the DCT) is a 4.3-m telescope designed and constructed for optical and near infrared astronomical observation. We present the evolution over time of LDT's image quality and ways to improve it, upgrades to the instrument suite, and lessons learned from operating during the pandemic.
  68. van Belle, G., Clark, J., Schmitt, H., et al., (including Noble, D., Coleman, T., Hardesty, B., Clark, W., Jones, K., Kingsley, B., Maier, E., Blomquist, S.), 2022, SPIE, 12183, 1218304, The Navy Precision Optical Interferometer: large-aperture observations and infrastructure improvements
    We have been progressing on our comprehensive program of improving high-resolution imaging at the Navy Precision Optical Interferometer (NPOI) hosted at Lowell Observatory's Anderson Mesa site, for the purpose of spatially resolved observations of faint objects at scales down to less than 1 milliarcsecond. The `PALANTIR' upgrade of NPOI has commenced with individually operating 1 meter PlaneWave PW1000 telescopes at the site, with integration of those telescopes into the array with interferometric operations expected in the near-term. These telescopes are housed in mobile domes for rapid relocation around the array, and are being augmented with adaptive optics. Another notable recent milestone has been the re-activation of full six-way on-sky operations with siderostat feeds during the summer of 2021. Additionally, our `NPOI Plus-Up' plan will implement sweeping infrastructure updates, improving and streamlining its operations. Upcoming Plus-Up work taking place over the next few years includes expansion of the operating infrastructure to the array's longest physical baselines at 432 meters, adding a near-infrared beam combiner, rehabilitation of the VISION visible combiner, modernization of the fast delay line control system, and implementation of the long delay lines in the framework of a beam train auto-aligner.
  69. Jorgensen, A., Jones, K., Noble, D., et al., (including van Belle, G.), 2022, SPIE, 12183, 121830O, Automation upgrades at the navy precision optical interferometer
    The Navy Precision Optical Interferometer (NPOI) is approaching 30 years of operational life. During that time it has carried out many observations of single and multiple star systems, and has seen upgrades to subsystems and expansion of capabilities. For the last couple of years there has been a major ongoing effort to expand the capabilities of the NPOI with new telescopes, new instruments, and completion of the bootstrapping and imaging capability that was part of the original NPOI design. As part of this upgrade we are also upgrading and replacing some electronic systems. Some technologies which were state-of-the art, e.g. VxWorks, have over the years been overtaken by inexpensive systems such as embedded microcontroller, consumer-grade compact system such as Raspberry Pi1 and Arduino,2 and inexpensive manufacture of simple and powerful custom PCBs. This makes it possible to incorporate remote controls of actuators which will be a major convenience compared to the existing system of manual controls.
  70. van Belle, G., Hillsberry, D., Piness, J., et al., 2022, SPIE, 12183, 121831D, Sub-milliarcsecond astronomical imaging: advancing space-based astronomical optical interferometry observatories with Optimast
    Astrophysical goals articulated in the recent Astronomy Decadal Review demand significant strides in high sensitivity, high spatial resolution observing. Current ground-based interferometric observatories have validated and demonstrated synthetic aperture observation, but are fundamentally limited in sensitivity by the Earth's atmosphere. Lowell Observatory and Redwire Space, Inc., have recently concluded NASA SBIR Phase II work in developing `Optimast' interferometry technologies which provide us with a toolkit for mission development. Optimast research included demonstrations of a prototype beam combiner, outboard feed optics tracking, and in-situ boom manufacturing for structurally connected free fliers. Our mission's roadmap includes affordable small demonstrators such as free fliers for flexible at-will observing of the entire sky, and lunar surface `suitcase' concepts for rapid, simple implementation of sensitive, high resolution facilities.
  71. Baines, E., Schmitt, H., Armstrong, J., et al., (including van Belle, G.), 2022, SPIE, 12183, 121832B, How much Is enough? Using the NPOI archive to characterize stellar diameter measurements
    The Navy Precision Optical Interferometer (NPOI) has been in operation since 1996, building a substantial data archive. This provided the opportunity to determine how many data points are needed for a single star's angular diameter fit to become stable as more data points were included. In an iterative process, we calculated the diameters for an ever-increasing number of data points for 31 stars. We found that at approximately 1,000 data points, the scatter in the diameter fits fell below 2%. Assuming a 3-telescope triangle and using 15 channels across a range of wavelengths, 1,000 data points equates to 22 to 25 bracketed observations, which can usually be accomplished in 2 to 4 nights. This will be a useful rule-of-thumb when planning observations and gathering data on single, symmetrical stars.
  72. Zafar, T., Lawrence, J., Zheng, J., et al., (including Kuehn, K.), 2022, SPIE, 12184, 1218417, MANIFEST@GMT science overview: a multi-interface, multi-mode instrument science and simulations
    The Many Instrument Fiber System (MANIFEST) is a facility fiber system for the Giant Magellan Telescope (GMT). MANIFEST will be capable of feeding current and upcoming GMT instruments light from the telescopes full 20-arcmin field of view. The MANIFEST concept uses "Starbugs" - self-motile fiber heads deployed on a glass plate. MANIFEST will enhance the capabilities of different optical and near-infrared spectrographs at the GMT by feeding fibres and providing simultaneous observations. We have so far developed 15 science cases for MANIFEST which are listed under five broad science themes. Many science cases from galactic surveys, nearby galaxy surveys, intergalactic medium tomography, and spatially resolved studies of distant universe are of interest. These science cases drive the instrument requirements, modes of observations, and operation conditions for MANIFEST. Defined from the science cases, MANIFEST offers nine different modes of observations including high multiplexing, multiple and high sensitivity integral-field spectroscopy, polarimetry, and near-infrared spectroscopy. We discuss in this paper the latest developments of GMT/MANIFEST.
  73. Viavattene, G., Pedichini, F., Cortecchia, F., et al., (including Keller, C.), 2022, SPIE, 12184, 121843U, ELVIS: the exoplanets at LBT with a visible IFS for SHARK-VIS
    The Exoplanets at LBT with a Visible IFS for SHARK-VIS (ELVIS) is an add-on imaging spectrograph to be integrated in the new LBT high-contrast high-resolution AO-assisted imager SHARK-VIS. ELVIS is optimized for a medium/high spectral resolution of 10-20k with a limited bandwidth around the H, and it is planned fed by a small core (10-20 m) multi mode fiber bundle providing about 140 spaxels on a field of view around 300300 sqmas. This instrument has a very compact design based on a VPH dispersing element to allow its installation within a standard 19" rack mount. As shown in the literature, young accreting sub-stellar and planetary companions are better detected and analyzed by these instruments allowing to reach contrast at least ten times fainter (in their H emission) with respect to standard imagers.
  74. Kuehn, K., Kuhlmann, S., Kehoe, R., et al., 2022, SPIE, 12188, 121885L, Advancing photonic technologies for ground-based infrared astronomy
    We seek to advance the capabilities of photonic technologies in support of ground-based infrared astronomy. Currently, observations in the wavelength range 1.0m < < 2.5m suffer from an irreducible background generated by emission from OH (hydroxyl) molecules in the upper atmosphere. However, narrow-band notch filters incorporated into the optical path of astronomical instruments can suppress this background with very little accompanying loss of signal from the astronomical sources of interest. Micron-scale ring resonators are one technology that provides a promising method of generating such notch filters. Building on our previous efforts in astrophotonic technology development, our current goals are 1) to optimize the design of ring resonators so that the notch filters they create provide greatest suppression at the wavelengths of the most prominent OH lines, and 2) to optimize the coupling of the resonator-equipped silicon devices with the input fibers (from the sky) and output fibers (to the spectrograph and detector) such that the throughput losses do not completely eliminate the signal-to-noise improvement gained from the OH suppression. To accomplish the former, we introduce heaters that can actively change the wavelength of the notch filters to match the OH emission lines, as well as mechanisms for polarization-dependent and -independent suppression. To accomplish the latter, we incorporate post-fabrication packaging of fibers to ensure optimal alignment.
  75. Leisawitz, D., Matsuo, T., Mosby, G., et al., (including van Belle, G.), 2022, SPIE, 12190, 121901G, The Japan-United States Infrared Interferometry Experiment (JUStIInE): balloon-borne pathfinder for a space-based far-IR interferometer
    The balloon-borne Japan-United States Infrared Interferometry Experiment (JUStIInE) is a pathfinder for the first space-based far-IR interferometer. JUStIInE will mature the system-level technology readiness of spatio-spectral far-IR interferometry and demonstrate this technique with scientific observations. Operating at wavelengths from 30 to 90 m, JUStIInE will provide unprecedented sub-arcsecond angular resolution and spectroscopic data. Our plan is to develop a cryogenic Michelson beam combiner and integrate it with an existing and tested telescope optical system and gondola from the Japanese Far-infrared Interferometric Telescope Experiment (FITE). With two JUStIInE balloon flights we plan to collect, calibrate, analyze, and publish scientific results based on the first far-IR spatio-spectral observations of young stellar objects, evolved stars, and the active galactic nucleus of NGC 1068. The NASA Astrophysics Roadmap envisages a future in which interferometry is applied across the electromagnetic spectrum, starting in the far-infrared. The Far-IR Probe recommended in the 2021 Decadal Survey presents an opportunity to take that important step. A Far-IR Probe mission based on this concept will enable us to understand terrestrial planet formation and spectroscopically study individual distant galaxies to understand the astrophysical processes that govern their evolution.
  76. Pandey, S., Krause, E., DeRose, J., et al., (including Kuehn, K.), 2022, PhRvD, 106, 043520, Dark Energy Survey year 3 results: Constraints on cosmological parameters and galaxy-bias models from galaxy clustering and galaxy-galaxy lensing using the redMaGiC sample
    We constrain cosmological parameters and galaxy-bias parameters using the combination of galaxy clustering and galaxy-galaxy lensing measurements from the Dark Energy Survey (DES) year-3 data. We describe our modeling framework and choice of scales analyzed, validating their robustness to theoretical uncertainties in small-scale clustering by analyzing simulated data. Using a linear galaxy-bias model and redMaGiC galaxy sample, we obtain 10% constraints on the matter density of the Universe. We also implement a nonlinear galaxy-bias model to probe smaller scales that includes parametrization based on hybrid perturbation theory and find that it leads to a 17% gain in cosmological constraining power. We perform robustness tests of our methodology pipeline and demonstrate stability of the constraints to changes in the theory model. Using the redMaGiC galaxy sample as foreground lens galaxies and adopting the best-fitting cosmological parameters from DES year-1 data, we find the galaxy clustering and galaxy-galaxy lensing measurements to exhibit significant signals akin to decorrelation between galaxies and mass on large scales, which is not expected in any current models. This likely systematic measurement error biases our constraints on galaxy bias and the S8 parameter. We find that a scale-, redshift- and sky-area-independent phenomenological decorrelation parameter can effectively capture this inconsistency between the galaxy clustering and galaxy-galaxy lensing. We trace the source of this correlation to a color-dependent photometric issue and minimize its impact on our result by changing the selection criteria of redMaGiC galaxies. Using this new sample, our constraints on the S8 parameter are consistent with previous studies and we find a small shift in the m constraints compared to the fiducial redMaGiC sample. We infer the constraints on the mean host-halo mass of the redMaGiC galaxies in this new sample from the large-scale bias constraints, finding the galaxies occupy halos of mass approximately 1.6 1013 M/h .
  77. Humes, O., Thomas, C., Emery, J., et al., (including Grundy, W.), 2022, PSJ, 3, 190, Ultraviolet Spectroscopy of Lucy Mission Targets with the Hubble Space Telescope
    The recently launched Lucy mission aims to understand the dynamical history of the solar system by examining the Jupiter Trojans, a population of primitive asteroids co-orbital with Jupiter. Using the G280 grism on the Hubble Space Telescope's Wide Field Camera 3, we obtained near-ultraviolet spectra of four of the five Lucy mission targets-(617) Patroclus-Menoetius, (11351) Leucus, (3548) Eurybates, and (21900) Orus-to search for novel spectral features. We observe a local reflectance minimum at 0.4 m accompanied by an increase in reflectance from 0.35 to 0.3 m in the spectra of Patroclus and Orus. We use the principles of Rayleigh scattering and geometric optics to develop a Hapke optical model to investigate whether this feature can be explained by the presence of submicroscopic grains on Trojan surfaces. The near-ultraviolet "bump" feature can be explained by scattering due to fine-grained opaques (iron, amorphous carbon, or graphite) with grain sizes ranging from 20 to 80 nm.
  78. Drlica-Wagner, A., Ferguson, P., Adamow, M., et al., (including Kuehn, K.), 2022, ApJS, 261, 38, The DECam Local Volume Exploration Survey Data Release 2
    We present the second public data release (DR2) from the DECam Local Volume Exploration survey (DELVE). DELVE DR2 combines new DECam observations with archival DECam data from the Dark Energy Survey, the DECam Legacy Survey, and other DECam community programs. DELVE DR2 consists of ~160,000 exposures that cover >21,000 deg2 of the high-Galactic-latitude (b > 10) sky in four broadband optical/near-infrared filters (g, r, i, z). DELVE DR2 provides point-source and automatic aperture photometry for ~2.5 billion astronomical sources with a median 5 point-source depth of g = 24.3, r = 23.9, i = 23.5, and z = 22.8 mag. A region of ~17,000 deg2 has been imaged in all four filters, providing four-band photometric measurements for ~618 million astronomical sources. DELVE DR2 covers more than 4 times the area of the previous DELVE data release and contains roughly 5 times as many astronomical objects. DELVE DR2 is publicly available via the NOIRLab Astro Data Lab science platform.
  79. Wetzell, V., Jeltema, T., Hegland, B., et al., (including Kuehn, K.), 2022, MNRAS, 514, 4696, Velocity dispersions of clusters in the Dark Energy Survey Y3 redMaPPer catalogue
    We measure the velocity dispersions of clusters of galaxies selected by the red-sequence Matched-filter Probabilistic Percolation (redMaPPer) algorithm in the first three years of data from the Dark Energy Survey (DES), allowing us to probe cluster selection and richness estimation, , in light of cluster dynamics. Our sample consists of 126 clusters with sufficient spectroscopy for individual velocity dispersion estimates. We examine the correlations between cluster velocity dispersion, richness, X-ray temperature, and luminosity, as well as central galaxy velocity offsets. The velocity dispersion-richness relation exhibits a bimodal distribution. The majority of clusters follow scaling relations between velocity dispersion, richness, and X-ray properties similar to those found for previous samples; however, there is a significant population of clusters with velocity dispersions that are high for their richness. These clusters account for roughly 22 per cent of the < 70 systems in our sample, but more than half (55 per cent) of < 70 clusters at z > 0.5. A couple of these systems are hot and X-ray bright as expected for massive clusters with richnesses that appear to have been underestimated, but most appear to have high velocity dispersions for their X-ray properties likely due to line-of-sight structure. These results suggest that projection effects contribute significantly to redMaPPer selection, particularly at higher redshifts and lower richnesses. The redMaPPer determined richnesses for the velocity dispersion outliers are consistent with their X-ray properties, but several are X-ray undetected and deeper data are needed to understand their nature.
  80. Moller, A., Smith, M., Sako, M., et al., (including Kuehn, K.), 2022, MNRAS, 514, 5159, The dark energy survey 5-yr photometrically identified type Ia supernovae
    As part of the cosmology analysis using Type Ia Supernovae (SN Ia) in the Dark Energy Survey (DES), we present photometrically identified SN Ia samples using multiband light curves and host galaxy redshifts. For this analysis, we use the photometric classification framework SUPERNNOVAtrained on realistic DES-like simulations. For reliable classification, we process the DES SN programme (DES-SN) data and introduce improvements to the classifier architecture, obtaining classification accuracies of more than 98 per cent on simulations. This is the first SN classification to make use of ensemble methods, resulting in more robust samples. Using photometry, host galaxy redshifts, and a classification probability requirement, we identify 1863 SNe Ia from which we select 1484 cosmology-grade SNe Ia spanning the redshift range of 0.07 < z < 1.14. We find good agreement between the light-curve properties of the photometrically selected sample and simulations. Additionally, we create similar SN Ia samples using two types of Bayesian Neural Network classifiers that provide uncertainties on the classification probabilities. We test the feasibility of using these uncertainties as indicators for out-of-distribution candidates and model confidence. Finally, we discuss the implications of photometric samples and classification methods for future surveys such as Vera C. Rubin Observatory Legacy Survey of Space and Time.
  81. Clark, C., van Belle, G., Horch, E., et al., (including von Braun, K.), 2022, AJ, 164, 33, The POKEMON Speckle Survey of Nearby M Dwarfs. I. New Discoveries
    M dwarfs are favorable targets for exoplanet detection with current instrumentation, but stellar companions can induce false positives and inhibit planet characterization. Knowledge of stellar companions is also critical to our understanding of how binary stars form and evolve. We have therefore conducted a survey of stellar companions around nearby M dwarfs, and here we present our new discoveries. Using the Differential Speckle Survey Instrument at the 4.3 m Lowell Discovery Telescope, and the similar NN-EXPLORE Exoplanet Stellar Speckle Imager at the 3.5 m WIYN telescope, we carried out a volume-limited survey of M-dwarf multiplicity to 15 parsecs, with a special emphasis on including the later M dwarfs that were overlooked in previous surveys. Additional brighter targets at larger distances were included for a total sample size of 1070 M dwarfs. Observations of these 1070 targets revealed 26 new companions; 22 of these systems were previously thought to be single. If all new discoveries are confirmed, then the number of known multiples in the sample will increase by 7.6%. Using our observed properties, as well as the parallaxes and 2MASS K magnitudes for these objects, we calculate the projected separation, and estimate the mass ratio and component spectral types, for these systems. We report the discovery of a new M-dwarf companion to the white dwarf Wolf 672 A, which hosts a known M-dwarf companion as well, making the system trinary. We also examine the possibility that the new companion to 2MASS J13092185-2330350 is a brown dwarf. Finally, we discuss initial insights from the POKEMON survey.
  82. Pravec, P., Thomas, C., Rivkin, A., et al., (including Moskovitz, N., Thirouin, A.), 2022, PSJ, 3, 175, Photometric Observations of the Binary Near-Earth Asteroid (65803) Didymos in 2015-2021 Prior to DART Impact
    We performed photometric observations of the binary near-Earth asteroid (65803) Didymos in support of the Double Asteroid Redirection Test (DART) mission that will test the Kinetic Impactor technology for diverting dangerous asteroids. It will hit the Didymos secondary, called Dimorphos, on 2022 September 26. We observed Didymos with 11 telescopes with diameters from 3.5 to 10.4 m during four apparitions in 2015-2021, obtaining data with rms residuals from 0.006 to 0.030 mag. We analyzed the light-curve data and decomposed them into the primary rotational and secondary orbital light curves. We detected 37 mutual eclipse/occultation events between the binary system components. The data presented here, in combination with 18 mutual events detected in 2003, provide the basis for modeling the Dimorphos orbit around the Didymos primary. The orbit modeling is discussed in detail by Scheirich & Pravec and Naidu et al. The primary light curves were complex, showing multiple extrema on some epochs. They suggest a presence of complex topography on the primary's surface that is apparent in specific viewing/illumination geometries; the primary shape model by Naidu et al. (Icarus 348, 113777, 2020) needs to be refined. The secondary rotational light-curve data were limited and did not provide a clear solution for the rotation period and equatorial elongation of Dimorphos. We define the requirements for observations of the secondary light curve to provide the needed information on Dimorphos's rotation and elongation when Didymos is bright in 2022 July-September before the DART impact.
  83. Thirouin, A., Sheppard, S., 2022, PSJ, 3, 178, Lightcurves and Rotations of Trans-Neptunian Objects in the 2:1 Mean Motion Resonance with Neptune
    We report the rotational lightcurves of 21 trans-Neptunian objects (TNOs) in Neptune's 2:1 mean motion resonance obtained with the 6.5 m Magellan-Baade telescope and the 4.3 m Lowell Discovery Telescope. The main survey's goal is to find objects displaying a large lightcurve amplitude that is indicative of contact binaries or highly elongated objects. In our sample, two 2:1 resonant TNOs showed a significant short-term lightcurve amplitude: 2002 VD130 and (531074) 2012 DX98. The full lightcurve of 2012 DX98 infers a periodicity of 20.80 0.06 hr and amplitude of 0.56 0.03 mag, whereas 2002 VD130 rotates in 9.85 0.07 hr with a 0.31 0.04 mag lightcurve amplitude. Based on lightcurve morphology, we classify (531074) 2012 DX98 as a likely contact binary but 2002 VD130 as a likely single elongated object. Based on our sample and the lightcurves reported in the literature, we estimate the lower percentage of nearly equal-sized contact binaries at only 7%-14% in the 2:1 resonance, which is comparable to the low fraction reported for the dynamically cold classical TNOs. This low contact binary fraction in the 2:1 Neptune resonance is consistent with the lower estimate of the recent numerical modeling. We report the Sloan g', r', and i' surface colors of 2002 VD130, which is an ultra-red TNO whereas 2012 DX98 is a very red object based on published surface colors.
  84. Lokken, M., Hlozek, R., van Engelen, A., et al., (including Kuehn, K.), 2022, ApJ, 933, 134, Superclustering with the Atacama Cosmology Telescope and Dark Energy Survey. I. Evidence for Thermal Energy Anisotropy Using Oriented Stacking
    The cosmic web contains filamentary structure on a wide range of scales. On the largest scales, superclustering aligns multiple galaxy clusters along intercluster bridges, visible through their thermal Sunyaev-Zel'dovich signal in the cosmic microwave background. We demonstrate a new, flexible method to analyze the hot gas signal from multiscale extended structures. We use a Compton y-map from the Atacama Cosmology Telescope (ACT) stacked on redMaPPer cluster positions from the optical Dark Energy Survey (DES). Cutout images from the y-map are oriented with large-scale structure information from DES galaxy data such that the superclustering signal is aligned before being overlaid. We find evidence of an extended quadrupole moment of the stacked y signal at the 3.5 level, demonstrating that the large-scale thermal energy surrounding galaxy clusters is anisotropically distributed. We compare our ACT DES results with the Buzzard simulations, finding broad agreement. Using simulations, we highlight the promise of this novel technique for constraining the evolution of anisotropic, non-Gaussian structure using future combinations of microwave and optical surveys.
  85. McKinnon, W., Mao, X., Schenk, P., et al., (including Grundy, W.), 2022, GeoRL, 49, e98406, Snow Crash: Compaction Craters on (486958) Arrokoth and Other Small KBOs, With Implications
    Evidence from Arrokoth and comets strongly suggests a very low density for this and similar small Kuiper belt objects. Plausible compositions imply high porosities, in excess of 70%, and low compaction crush strengths. If so, impact craters on Arrokoth (especially Sky, its largest) formed largely by compaction of pore space and material displacement. This is consistent with geological evidence from New Horizons imaging. High porosity reduces cratering efficiency in the gravity regime whereas compaction moves it toward crush strength scaling and increased efficiency. Compaction also guarantees that most impactor kinetic energy is taken up as waste heat near the impact point, with momentum transferred to the rest of the body by elastic waves only. Monte Carlo simulations of Sky-forming conditions indicate that the momentum imparted likely separated Arrokoth's two lobes, but displacement was limited by dissipation at the neck between them. Unusual strength properties are not required to preserve Arrokoth's bilobate configuration.
  86. Seligman, D., Rogers, L., Cabot, S., et al., (including Kareta, T.), 2022, PSJ, 3, 150, The Volatile Carbon-to-oxygen Ratio as a Tracer for the Formation Locations of Interstellar Comets
    Based on the occurrence rates implied by the discoveries of 1I/'Oumuamua and 2I/Borisov, the forthcoming Rubin Observatory Legacy Survey of Space and Time (LSST) should detect one interstellar object every year. We advocate for future measurements of the production rates of H2O, CO2, and CO in these objects to estimate their carbon-to-oxygen ratios, which trace formation locations within their original protoplanetary disks. We review similar measurements for solar system comets, which indicate formation interior to the CO snow line. By quantifying the relative processing in the interstellar medium and solar system, we estimate that production rates will not be representative of primordial compositions for the majority of interstellar comets. Preferential desorption of CO and CO2 relative to H2O in the interstellar medium implies that measured C/O ratios represent lower limits on the primordial ratios. Specifically, production rate ratios of Q(CO)/Q(H2O) < 0.2 and Q(CO)/Q(H2O) > 1 likely indicate formation interior and exterior to the CO snow line, respectively. The high C/O ratio of 2I/Borisov implies that it formed exterior to the CO snow line. We provide an overview of the currently operational facilities capable of obtaining these measurements that will constrain the fraction of ejected comets that formed exterior to the CO snow line. This fraction will provide key insights into the efficiency of and mechanisms for cometary ejection in exoplanetary systems.
  87. Rivkin, A., Emery, J., Howell, E., et al., (including Kareta, T.), 2022, PSJ, 3, 153, The Nature of Low-albedo Small Bodies from 3 m Spectroscopy: One Group that Formed within the Ammonia Snow Line and One that Formed beyond It
    We present evidence, via a large survey of 191 new spectra along with previously published spectra, of a divide in the 3 m spectral properties of the low-albedo asteroid population. One group ("sharp types," or STs, with band centers <3 m) has a spectral shape consistent with carbonaceous chondrite meteorites, while the other group ("not sharp types," or NSTs, with bands centered >3 m) is not represented in the meteorite literature but is as abundant as the STs among large objects. Both groups are present in most low-albedo asteroid taxonomic classes, and, except in limited cases, taxonomic classifications based on 0.5-2.5 m data alone cannot predict whether an asteroid is an ST or NST. Statistical tests show that the STs and NSTs differ in average band depth, semimajor axis, and perihelion at confidence levels 98% while not showing significant differences in albedo. We also show that many NSTs have a 3 m absorption band shape like comet 67P and likely represent an important small-body composition throughout the solar system. A simple explanation for the origin of these groups is formation on opposite sides of the ammonia snow line, with the NST group accreting H2O and NH3 and the ST group only accreting H2O, with subsequent thermal and chemical evolution resulting in the minerals seen today. Such an explanation is consistent with recent dynamical modeling of planetesimal formation and delivery and suggests that much more outer solar system material was delivered to the main asteroid belt than would be thought based on the number of D-class asteroids found today.
  88. Metcalfe, T., Finley, A., Kochukhov, O., et al., (including Clark, C.), 2022, ApJL, 933, L17, The Origin of Weakened Magnetic Braking in Old Solar Analogs
    The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. The rate of angular momentum loss depends on the strength and morphology of the magnetic field, the mass-loss rate, and the stellar rotation period, mass, and radius. Previous observations suggested a shift in magnetic morphology between two F-type stars with similar rotation rates but very different ages (88 Leo and CrB). In this Letter, we identify a comparable transition in an evolutionary sequence of solar analogs with ages between 2-7 Gyr. We present new spectropolarimetry of 18 Sco and 16 Cyg A and B from the Large Binocular Telescope, and we reanalyze previously published Zeeman Doppler images of HD 76151 and 18 Sco, providing additional constraints on the nature and timing of this transition. We combine archival X-ray observations with updated distances from Gaia to estimate mass-loss rates, and we adopt precise stellar properties from asteroseismology and other sources. We then calculate the wind braking torque for each star in the evolutionary sequence, demonstrating that the rate of angular momentum loss drops by more than an order of magnitude between the ages of HD 76151 and 18 Sco (2.6-3.7 Gyr) and continues to decrease modestly to the age of 16 Cyg A and B (7 Gyr). We suggest that this magnetic transition may represent a disruption of the global dynamo arising from weaker differential rotation, and we outline plans to probe this phenomenon in additional stars spanning a wide range of spectral types.
  89. Cawthon, R., Elvin-Poole, J., Porredon, A., et al., (including Kuehn, K.), 2022, MNRAS, 513, 5517, Dark Energy Survey Year 3 results: calibration of lens sample redshift distributions using clustering redshifts with BOSS/eBOSS
    We present clustering redshift measurements for Dark Energy Survey (DES) lens sample galaxies used in weak gravitational lensing and galaxy clustering studies. To perform these measurements, we cross-correlate with spectroscopic galaxies from the Baryon Acoustic Oscillation Survey (BOSS) and its extension, eBOSS. We validate our methodology in simulations, including a new technique to calibrate systematic errors that result from the galaxy clustering bias, and we find that our method is generally unbiased in calibrating the mean redshift. We apply our method to the data, and estimate the redshift distribution for 11 different photometrically selected bins. We find general agreement between clustering redshift and photometric redshift estimates, with differences on the inferred mean redshift found to be below |z| = 0.01 in most of the bins. We also test a method to calibrate a width parameter for redshift distributions, which we found necessary to use for some of our samples. Our typical uncertainties on the mean redshift ranged from 0.003 to 0.008, while our uncertainties on the width ranged from 4 to 9 per cent. We discuss how these results calibrate the photometric redshift distributions used in companion papers for DES Year 3 results.
  90. Stone, Z., Shen, Y., Burke, C., et al., (including Kuehn, K.), 2022, MNRAS, 514, 164, Optical variability of quasars with 20-yr photometric light curves
    We study the optical gri photometric variability of a sample of 190 quasars within the SDSS Stripe 82 region that have long-term photometric coverage during ~1998-2020 with SDSS, PanSTARRS-1, the Dark Energy Survey, and dedicated follow-up monitoring with Blanco 4m/DECam. With on average ~200 nightly epochs per quasar per filter band, we improve the parameter constraints from a Damped Random Walk (DRW) model fit to the light curves over previous studies with 10-15 yr baselines and 100 epochs. We find that the average damping time-scale DRW continues to rise with increased baseline, reaching a median value of ~750 d (g band) in the rest frame of these quasars using the 20-yr light curves. Some quasars may have gradual, long-term trends in their light curves, suggesting that either the DRW fit requires very long baselines to converge, or that the underlying variability is more complex than a single DRW process for these quasars. Using a subset of quasars with better-constrained DRW (less than 20 per cent of the baseline), we confirm a weak wavelength dependence of DRW0.51 0.20. We further quantify optical variability of these quasars over days to decades time-scales using structure function (SF) and power spectrum density (PSD) analyses. The SF and PSD measurements qualitatively confirm the measured (hundreds of days) damping time-scales from the DRW fits. However, the ensemble PSD is steeper than that of a DRW on time-scales less than ~ a month for these luminous quasars, and this second break point correlates with the longer DRW damping time-scale.
  91. DeMeo, F., Burt, B., Marsset, M., et al., (including Moskovitz, N.), 2022, Icar, 380, 114971, Connecting asteroids and meteorites with visible and near-infrared spectroscopy
    In this work we identify spectral similarities between asteroids and meteorites. Using spectral features such as absorption bands and spectral curvature, we identify spectral matches between 500 asteroid spectra and over 1,000 samples of RELAB meteorite spectra over visible plus near-infrared wavelengths (0.45- 2 . 5 m). We reproduce and confirm many major and previously known meteorite-asteroid connections and find possible new, more rare or less-established connections. Well-established connections include: ordinary chondrites with S-complex asteroids; pristine CM carbonaceous chondrites with Ch-type asteroids and heated CMs with C-type asteroids ; HED meteorites with V-types; enstatite chondrites with Xc-type asteroids; CV meteorites with K-type asteroids; Brachinites, Pallasites and R chondrites with olivine-dominated A-type asteroids.

    In addition to the link between ordinary chondrite meteorites with S-complex asteroids, we find a trend from Q, Sq, S, Sr to Sv correlates with LL to H, with Q-types matching predominately to L and LL ordinary chondrites, and Sr and Sv matching predominantly with L and H ordinary chondrites. We find ordinary chondrite samples that match to the X-complex. These are measurements of slabs and many are labeled as dark or black (shocked) ordinary chondrites. We find carbonaceous chondrite samples having spectral slopes large enough to match D-type asteroid spectra.

    We find in many cases the asteroid type to meteorite type links are not unique, for classes with and without distinct spectral features. While there are examples of dominant matches between an asteroid class and meteorite class that are well established, there are less common but still spectrally compatible matches between many asteroid types and meteorite types. This result emphasizes the diversity of asteroid and meteorite compositions and highlights the degeneracy of classification by spectral features alone requiring additional measurements to firmly establish asteroid-meteorite links. Recent and upcoming spacecraft missions will shed light on the compositions of many of the asteroid classes, particularly those without diagnostic features, (C-, B-, X-, and D-types), with measurements of C-type Ceres, C-type Ryugu, B-type Bennu, M-type Psyche, and C-, P-, and D-types as part of the Lucy mission.

  92. Archer, H., Cigan, P., Elmegreen, B., et al., (including Hunter, D.), 2022, hst, 17068, Young Stars and Gas Structure within the ALMA Coverage of Dwarf Irregular Galaxy WLM
    We request HST WFC3/UVIS and WFC3/IR observations of the areas within local dwarf irregular galaxy WLM that have been surveyed with ALMA in CO(2-1) and CO(1-0) in order to dissect and understand the star forming regions in this low-metallicity environment. WLM has an oxygen abundance that is 13% of solar, and the structure of the molecular clouds at these low metallicities is fundamentally different from those found in higher metallicity spirals such as the Milky Way. Recent analysis of star forming regions with CO cores within WLM raised questions about the role of these cores in the overall star forming event in these regions. The proposed HST observations from 0.275 to 1.6 microns will allow (1) measurements of the age and extinction toward massive stars that have formed in the star-forming regions, (2) calculation of the ionized gas mass in the star-forming regions, (3) constraint of the cloud boundaries, (4) identification of YSOs that are forming in the CO cores and determination of their evolutionary stage, (5) mapping of the extinction as a tracer of the gas within the star-forming regions, and (6) placement of the CO cores in the context of the gas and dust. This is crucial for our understanding of the role of the small CO cores in low metallicity star-forming regions.
  93. Messa, M., Adamo, A., Calzetti, D., et al., (including Hunter, D.), 2022, hst, 17151, Massive star clusters in low star formation regime dwarfs?
    We propose to determine whether the high end of the star clusters mass function is truncated in low density dwarf galaxies. We will image the cluster populations of 10 nearby dwarfs, aiming at collecting a statistically significant sample of clusters, about 150 across all galaxies, in order to overcome current uncertainties driven by low-number statistics. The proposed 5 bands (NUV-U-B-V-I) observations leverage the UV and high angular resolution capabilities of HST to accurately measure the physical parameters (age, mass, extinction) of the star clusters. We will be able to establish whether and how star formation depends on the local or global galaxy environment, and how much of the star formation in dwarfs takes places in bound clusters, therefore testing whether low-density dwarf galaxies are scaled-down versions of spirals or are instead simply less efficient at forming bound structures. The cumulative star cluster population will provide enough statistics to measure the upper mass truncation with an accuracy of better than 0.5 dex or to robustly rule out its presence, enabling us to determine whether the dearth of observed massive clusters in dwarfs is driven by stochastic sampling at the high mass end (a direct consequence of their low SFRs) or by inhibiting mechanisms driven by physical properties (e.g. the low-density environment in dwarfs). Young massive clusters can be significant sources of ionizing and mechanical energy. Determining the environmental conditions that favor the formation of massive clusters could help isolate the sources of reionization of the early Universe, one of the key science goals of the just-launched JWST.
  94. Thilker, D., Barnes, A., Bigiel, F., et al., (including Hunter, D.), 2022, hst, 17189, A panoramic study of low-density star formation in XUV disk galaxy NGC 3621: Testing for environmental dependency of clusters, OB associations, and the stellar hierarchy
    We propose an efficient yet panoramic UV-optical survey of the extended UV disk galaxy NGC 3621, with the goal of decisively evaluating various environmental dependencies of stellar cluster and OB association populations. Such work is very challenging in the regime of low-density star formation (SF) because large areas must be observed by HST to accumulate statistical samples. Consequently, our knowledge of the SF process, its products, and associated feedback in this extreme, but important, regime is woefully incomplete. Our program addresses this shortcoming in a finely controlled experiment using an otherwise well-studied target. The union of NGC 3621's inner and XUV disks presents an ideal test-bed because the local physical conditions change in a remarkably continuous radial manner, across our ~1400 sq.kpc HST footprint, that fully probes gradients in metallicity, plus stellar mass, gas mass and star formation rate surface density. Cluster and association counts will be high enough to bin versus environment for all our goals: (1) We will test predictions of SF modeling in low-density environments. Our program will provide decisive constraint on the extreme low end of predicted cluster formation efficiency, inform environment-driven models of cluster morphology, and determine whether continually dispersing remnants of SF activity are consistent with expectations. (2) The census of stochastic low-mass clusters and associations will provide a testbed for new models / analysis methods relevant to low-density SF. Our project is a vital step toward a full theoretical picture of SF and galaxy evolution in the vast majority of HI-dominated gas out to high redshift.
  95. Massey, P., Aadland, E., Hillier, D., et al., (including Neugent, K.), 2022, hst, 17193, WO-type Wolf-Rayet Stars: The Last Hurrah of Massive Stars
    The WO class of Wolf-Rayet (WR) stars represent the most evolved type of massive star: their last hurrah before they undergo core-collapse. Abundance determinations of WOs thus give us a glimpe of the nucleosynthsis of massive stars at the very end of their lives, providing an unprecedented test of stellar evolutionary theory. We have recently finished an analysis of two WOs in the Large Magellanic Cloud (LMC) in order to determine their physical properties, including their abundances. Our results imply that the nuclear reaction rate for 12C+4He-->16O (long known to be uncertain) must be significantly lower than what is used in modern evolutionary models. This has enormous implications: among other things, it would eliminate the conflict between the theoretical black hole upper mass gap and the large black hole masses revealed by various gravitational wave events. Yet, our result hinges on the analysis of only two stars. WO-type WRs are rare: there are only three in the LMC, and the handful known in the Milky Way and in other galaxies are too reddened or distant to obtain the high-quality UV spectra necessary for their analysis. Unfortunately, the third LMC WO star, LH41-1042, has a companion only 0.1" away. However, by carefully aligning one of the narrow STIS slits, we can obtain a nearly uncontaminated spectrum of this third WO with just seven orbits. These data will provide an important test of our conclusion that the 12C+4He-->16O nuclear reaction rate is too high. LH41-1042 is the only remaining WO star that can be observed in both the UV and optical; obtaining these data can only be done with HST.
  96. Proudfoot, B., Grundy, W., Ragozzine, D., et al., 2022, hst, 17206, Investigating Planet Formation in the Cold Classical TNOs Through Non-Keplerian Analysis
    The Cold Classical Transneptunian objects (TNOs) are one of the least processed solar system subpopulations, making them a perfect place to test planet formation hypotheses. One of the most favored planetary formation models is the streaming instability, which predicts that binaries should be extremely common, especially among the Cold Classical. It also predicts that the spins of individual binary components will be well aligned with the binary orbit. Unfortunately, to date, this prediction has been difficult to test, but with increasingly long observational baselines, non-Keplerian orbital analysis is able to precisely measure both the shapes and spin poles of individual binary components. With these measurements, a quantitative test of the streaming instability model of planetesimal formation can be completed. In this program, we request 8 orbits to precisely measure the spin poles and shapes of Cold Classical TNOs, which will enable a detailed test of planet formation models.
  97. West, M., De Propris, R., Gregg, M., 2022, hst, 17212, Caught in the Act: The Hierarchical Formation of Abell 1185
    Abell 1185 is a nearby example of a rich galaxy cluster still undergoing violent hierarchical assembly. Its brightest member galaxy, NGC 3550, is offset by 150 kpc from the cluster's dynamical center and is in the throes of cannibalizing several neighbors. Abell 1185 is also home to a population of intergalactic globular clusters, as well as the interacting system Arp 105, a spectacular collision between two galaxies that has spawned a compact region of intense star formation known as Ambartsumian's Knot as well as a 100-kpc-long tidal tail with embedded star clusters and newborn dwarf galaxies. Abell 1185 offers a unique opportunity to witness the ongoing birth of a dynamically young cluster and its constituents, a present-day analog to cluster formation at earlier epochs. We propose to carry out a comprehensive WFC3+ACS imaging survey of A1185 to learn more about the ongoing creation of galactic and intergalactic stellar populations in this dynamic environment. The resulting dataset will be of comparable legacy value to the ACS Treasury Survey of the Coma Cluster (GO 10861) for a fraction of the investment of time, providing a snapshot of a rich cluster environment that represents an important earlier stage in galaxy cluster evolution.
  98. Gatti, M., Pandey, S., Baxter, E., et al., (including Kuehn, K.), 2022, PhRvD, 105, 123525, Cross-correlation of Dark Energy Survey Year 3 lensing data with ACT and Planck thermal Sunyaev-Zel'dovich effect observations. I. Measurements, systematics tests, and feedback model constraints
    We present a tomographic measurement of the cross-correlation between thermal Sunyaev-Zel'dovich (TSZ) maps from Planck and the Atacama Cosmology Telescope and weak galaxy lensing shears measured during the first three years of observations of the Dark Energy Survey. This correlation is sensitive to the thermal energy in baryons over a wide redshift range and is therefore a powerful probe of astrophysical feedback. We detect the correlation at a statistical significance of 21 , the highest significance to date. We examine the TSZ maps for potential contaminants, including cosmic infrared background and radio sources, finding that cosmic infrared background has a substantial impact on our measurements and must be taken into account in our analysis. We use the cross-correlation measurements to test different feedback models. In particular, we model the TSZ using several different pressure profile models calibrated against hydrodynamical simulations. Our analysis marginalizes over redshift uncertainties, shear calibration biases, and intrinsic alignment effects. We also marginalize over m and 8 using Planck or DES priors. We find that the data prefer the model with a low amplitude of the pressure profile at small scales, compatible with a scenario with strong active galactic nuclei feedback and ejection of gas from the inner part of the halos. When using a more flexible model for the shear profile, constraints are weaker, and the data cannot discriminate between different baryonic prescriptions.
  99. Pandey, S., Gatti, M., Baxter, E., et al., (including Kuehn, K.), 2022, PhRvD, 105, 123526, Cross-correlation of Dark Energy Survey Year 3 lensing data with ACT and P l a n c k thermal Sunyaev-Zel'dovich effect observations. II. Modeling and constraints on halo pressure profiles
    Hot, ionized gas leaves an imprint on the cosmic microwave background via the thermal Sunyaev-Zel'dovich (tSZ) effect. The cross-correlation of gravitational lensing (which traces the projected mass) with the tSZ effect (which traces the projected gas pressure) is a powerful probe of the thermal state of ionized baryons throughout the Universe and is sensitive to effects such as baryonic feedback. In a companion paper (Gatti et al. Phys. Rev. D 105, 123525 (2022)), we present tomographic measurements and validation tests of the cross-correlation between Galaxy shear measurements from the first three years of observations of the Dark Energy Survey and tSZ measurements from a combination of Atacama Cosmology Telescope and Planck observations. In this work, we use the same measurements to constrain models for the pressure profiles of halos across a wide range of halo mass and redshift. We find evidence for reduced pressure in low-mass halos, consistent with predictions for the effects of feedback from active Galactic nuclei. We infer the hydrostatic mass bias (B M500 c/MSZ) from our measurements, finding B =1.8 0.1 when adopting the Planck-preferred cosmological parameters. We additionally find that our measurements are consistent with a nonzero redshift evolution of B , with the correct sign and sufficient magnitude to explain the mass bias necessary to reconcile cluster count measurements with the Planck-preferred cosmology. Our analysis introduces a model for the impact of intrinsic alignments (IAs) of galaxy shapes on the shear-tSZ correlation. We show that IA can have a significant impact on these correlations at current noise levels.
  100. Martinez, Z., Hunter, D., Elmegreen, B., 2022, AAS, 54, 103.01, Looking for a Relationship between Star Formation and Turbulence in THINGS Galaxies
    We have examined the relationship between star formation and turbulence in a sample of 11 galaxies from The HI Nearby Galaxy Survey (THINGS). The sample contains one dwarf irregular galaxy and 10 spiral galaxies. To analyze a potential relationship, we trace the turbulent motions in the HI gas maps from THINGS and the star formation rates in far-ultraviolet (FUV) images from the NASA Galaxy Evolution Explorer (GALEX) and construct radial profiles and pixel-by-pixel plots of certain parameters. We used radial profiles to remove the underlying disk from the pixel-pixel plots. The parameters include star formation rate density (SFRD), kinetic energy density (KED), velocity dispersion (Vdisp), and mass surface density (HI). These plots give us a broad idea of what the relationships between SFRD and KED, Vdisp, and HI look like. We find that there is, at best, a weak correlation between star formation and turbulence, which suggests that star formation is not a major driver of turbulence in atomic gas on the spatial scales of our survey. Additionally, we find that the relationships between these parameters are comparable in dwarfs and spirals suggesting that similar mechanisms are at play in both types of galaxies. This work was funded by NSF grants #1852478 and #1950901 to Northern Arizona University for its REU program.
  101. Hanley, J., 2022, AAS, 54, 134.01, Mars with a Pinch of Salt
    Salts are found throughout the Solar System, and are an important factor in the stability of water, as well as potential habitability. Different salts will affect the stability of water to varying degrees. Chlorine salts (chlorides, perchlorates, and chlorates), can suppress the freezing temperature of water down to ~200 K. They also slow down the evaporation rate, extending the lifetime of the liquid water solution. The local relative humidity plays a significant role in the stability of these salts, in both their liquid and solid phases. Salts can undergo deliquescence when the relative humidity exceeds a given threshold, forming liquid droplets. Some halophiles have been known to utilize these droplets for active metabolism. On Mars, chlorides have been found at every landing site, and perchlorates have been detected by Phoenix in the north polar plains, by Curiosity at Gale Crater, and by Perseverance in Jezero Crater. Reanalysis of Viking data suggests perchlorates could have been present there as well. Chlorates, which are almost as stable as perchlorates, are found on Earth everywhere that perchlorates exist, making them likely to be present on Mars too. Other oxidized chlorine salts may be present in limited quantities as precursors to the formation of perchlorate.

    Chlorine salts may also play a role in the mechanical properties of the regolith, as well as the stability of subsurface water. High soil cohesion was encountered at the Phoenix landing site making sample analysis challenging; such cohesion may result from hydrated salts and eutectic brines bonding grains together at their contacts by wetting, or from dehydrated salts crystallizing at grain contacts. Changes in hydration state with time (such as diurnally or seasonally) may then result in correlated changes in cohesive properties with time.

    It is imperative to study not only how these salts interact with their environment, but also how we detect and distinguish them. Reference spectra of surface materials at relevant temperatures are critical for deriving abundance estimates through spectral modeling. I will present laboratory measurements and modeling of salt, water and/or regolith interactions, as well as spectra of various chlorine-salt hydrates to aid in their identification.

  102. Clark, C., van Belle, G., 2022, AAS, 54, 208.05D, Looking out for the Little Guys: Measuring M-Dwarf Multiplicity with High-Resolution Imaging
    The M dwarfs comprise over 70% of the stars in our galaxy, and have been established as the most favorable targets for exoplanet detection and characterization using current instrumentation. However, unresolved stellar companions can contaminate the light curves of transiting planets, resulting in underestimated planet radii, skewed planet radius distributions and occurrence rates, incorrect characterization of both stars' properties, and a bias against detecting Earth-sized planets with transit surveys such as TESS. We therefore followed up 58 M-dwarf TESS Objects of Interest using speckle imagers around the world, and found that the orbital period distribution of stellar companions to planet-hosting M dwarfs is shifted to longer periods compared to the expected distribution for field M dwarfs. Additionally, in order to obtain a control sample of M dwarfs not seen to show a transit event, we carried out the POKEMON speckle survey of nearby M dwarfs. POKEMON is volume-limited through M9 out to 15 pc, with additional brighter targets to 25 pc. In total, we obtained multiplicity measurements for 1070 nearby M dwarfs, and revealed 27 new stellar companions, resulting in an 8% increase in known stellar companions to the stars in our sample. Finally, we present the Quad-camera Wavefront-sensing Six-channel Speckle Interferometer, a next-generation speckle imager we designed and constructed for the 4.3-m Lowell Discovery Telescope that allows us to better detect and characterize low-mass pairs.
  103. Holbrook, J., Adams, D., 2022, AAS, 54, 219.02, A New Observatory Is Coming to Your Neighborhood, Part 2: The Enacted Scenario The Proposed Telescope, The County Planning Office's Response, The Heritage Alliance's Position
    New observatories, new telescopes, and new instruments are among the many things that make astrophysics cutting edge. What is proposed here is the mythical next big radio telescope (OGRE). This is explored through a hypothetical example enacted by the presentation team. The County Planning Office will present how the nearby town and the county will benefit from the building of the mythical radio telescope. Included will be how many jobs will be created, important for a relatively poor county. This will outline astronomy's position in the matter. After hearing the presentation from the Scientists proposing the telescope and the response of the County Planning Office, next the Heritage Alliance takes the podium. The Heritage Alliance is concerned about the mythical telescope endangering local historical sites and those yet to be discovered. They present their numerous objections to moving forward with this radio telescope project.
  104. Biddle, L., Prato, L., Llama, J., 2022, AAS, 54, 237.04D, Stellar Activity and the Planet-Star Connection
    A major unanswered question in exoplanet science is the pathway for planetary formation and evolution. One approach to this problem is to accurately infer the histories of planets by comparing the demographics of late-age planetary systems to those of young systems. But, in contrast to the wealth of exoplanet discoveries at late ages, there are currently only a handful of confirmed planets at early ages (<10 Myr), and only one confirmed hot Jupiter (CI Tau b) orbiting a Classical T Tauri Star (CTTS). The severe deficit of young planets drives the motivation to find more of them. Doing so would provide concrete evidence for or against migration as well as timestamp the state of their atmospheric evolution. However, variability of CTTS is strong and occurs over a range of timescales, which can hinder the transit and RV detectability of young close-in planets. Intense magnetic activity in CTTS occurs in the form of long-lived cold spots and accretion hot spots which can mimic planetary signatures or drown them out entirely. Additionally, the high rate of energetic events generated by accretion shocks and flares is likely to affect the properties of the circumstellar disk and orbiting planets. The effects of CTTS's stellar activity therefore offer incentive to characterize these sources of variability to (1) tease out the observational signatures of newly-formed planets and (2) understand the impact that high-energy magnetic events have on the evolution of planets and protoplanetary disks. Using CI Tau b as an example, I present a novel method for detecting close-in planets around CTTS based on the planet's interaction with the circumstellar disk, driving pulsed accretion onto the star over the timescale of the planet's orbit. I discuss how this method can be used to detect more young close-in planets like CI Tau b. I also provide a diagnosis of the astrophysical contributions to the total photometric variability of CTTS through both an observational and computational lens.
  105. Massey, P., Aadland, E., Hillier, D., et al., (including Neugent, K.), 2022, AAS, 54, 327.05, WO-type Wolf-Rayet Stars: The Last Hurray of Massive Stars
    The most massive stars spend their helium burning lives as Wolf-Rayet (WR) stars, whose spectra are characterized by broad, strong emission lines. The majority of WRs are classified as either WN- or WC-type, depending upon whether their spectra show the products of hydrogen burning (helium and nitrogen) or helium burning (carbon and oxygen) at their surfaces. This represents an evolutionary sequence, with WCs being more highly evolved than WNs. A few percent of WRs, however, are classified as WO-type. Spectroscopically, these WO-type WRs are nearly indistinguishable from high-excitation WC types, but contain strong OVI 3811,34 emission. It has long been thought that this high-excitation line is indicative of high oxygen abundances, which would suggest that the WOs are even more evolved than the WCs, and hence likely the last stage before the core-collapse supernova stage. Alternatively, the WOs might be simply hotter versions of WCs. No previous studies have successfully fit the OVI 3811,34 feature, and therefore results on the abundances are suspect. We have completed the analysis of six WCs and two WOs (all in the LMC) using high quality UV, optical, and NIR spectra. Using the latest version of the radiative transfer code CMFGEN, we now obtain excellent fits to all of the lines, including the OVI 3811,34 doublet. We find that indeed the WOs have less helium and more carbon than the WCs, indicating that they are more evolved. However, ironically, their strong OVI 3811,34 lines are due to higher temperatures, and not more oxygen. A comparison of our results with single-star Geneva and binary BPASS evolutionary models show that while many properties match, there is more carbon and less oxygen in the WOs than either evolutionary model predicts. This discrepancy may be due to the large uncertainty in the 12C(alpha)16O nuclear reaction rate. We find that if the commonly adopted rate is decreased by a factor of 25-50%, then there would be a good match with the observations. The WOs are indeed more evolved than the WCs based on their lower helium content, and they are near the end of their nuclear-burning lives.

    This work comprises the PhD thesis of co-author Erin Aadland, who unfortunately could not be here to present the results herself. The study has been supported primarily through the NASA ADAP grant 80NSSC18K0729, with the ground-based observing supported through the National Science Foundation grant AST-1612874. Partial support was also provided by the Lowell Slipher Society funds. We also acknowledge support from STScI/NASA, through GO-5460, GO-5723, GO-12940, and GO-13781, AR-14568, and AR-16131

  106. Pasachoff, J., Boris, T., Lockwood, C., et al., (including Knowlton, P.), 2022, AAS, 54, 332.09, Preliminary Report on the December 4, 2021, Solar Eclipse Antarctic Expeditions
    We give a preliminary report on results gathered from our three successful expeditions to the December 4, 2021, total solar eclipse, whose totality passed over Antarctica and adjacent ocean. One of our groups was on a chartered LATAM Boeing 787 Dreamliner that flew eastward from Punta Arenas, Chile at 41,000 ft (a second 787 was 1000 feet lower). Eastward of the Falkland Islands the aircraft turned southwest for a totality run as the upper of two planes with paths plotted by Glenn Schneider to observe totality a few degrees above the horizon out the left-hand windows from near the sunrise point. Our group carried cameras with telephotos and 3 spectrographs from Voulgaris (Icarus Optomechanics), and observed a measured 1 m 52 s of totality (07:22:35.1 to 07:04:26.6 UTC; middle of eclipse: 07:03:30.85 -56.167825S -45.209159W). We also worked with four people including Boris, Lockwood, and equipment, who flew to Union Glacier, on the Antarctic continent (Latitude -79.76, Longitude -82.85). In addition to astronomical equipment to image totality at an altitude of about 14 above the horizon, they sent back a livestream to NASA.gov and the NASA YouTube channel. Further, Rojo, a professor of astronomy at the University of Chile, joined the official expedition carried by the Chilean Air Force to spend two weeks on Union Glacier, Antarctica, conducting that expedition's only astronomical observations. He carried Celestron, Sony, Canon, and Nikon telephotos; with Sony, Nikon, and Canon cameras, much of the equipment from Williams College; with filters by Questar and Thousand Oaks Optical; and an Icarus Optomechanics spectrograph from Voulgaris.

    In addition, efforts by the AAS Eclipse Task Force's Formal Education working group are on-going, in preparation for the annular 2023 and total 2024 solar eclipses.

    JMP's current research about eclipses is sponsored by grant AGS-1903500 of the Solar Terrestrial Program, Atmospheric and Geospace Sciences Division of the NSF, succeeding AGS-1602461 from the period of the 2017 eclipse. We thank Williams College for additional student expeditionary support from the Freeman Foote endowment. We thank Tim Todd of TEI Tours and Travel, for his travel arrangements; John Beattie for on-site arrangements, and Mark Sood of A Classic Tours Collection for additional assistance.

  107. Adams, D., 2022, AAS, 54, 349.01, Not at all Sad: The Heritage of Arabian Astronomy's "Auspicious Asterisms" from Sadachbia to Sadalsuud
    The region of sky spanning Capricornus, Aquarius, and western Pegasus contains a large number of third-magnitude stars, many of which bear namesapproved by the IAU Working Group on Star Namesthat reflect a common origin in indigenous Arabian astronomy. Although only a few of these Arabic-derived star names in use today begin with the prefix "Sad-", each of these stars formerly belonged to Arabian asterisms that bore formulaic Arabic names that began with the term sad, which indicated something auspicious, commonly a star or asterism. These formulaic star namesknown collectively in Arabic as "the Auspicious Asterisms" (as-suud)appeared in this particular region of sky alone, and the resulting collection of ten asterisms (mostly pairs of stars) rose heliacally within the space of just five weeks, from mid-January to mid-February, as viewed from Arabia in the 9th century CE.

    Drawing from 9th and 10th century CE Arabic texts by Qutrub (d. 821 CE), Ibn Qutayba (d. 889 CE), and as-Sufi (d. 986 CE), this talk reveals the unique heritage of indigenous Arabian astronomy in this region of the sky. The research begins by locating the group of ten asterisms in the modern sky and connecting the roots of their Arabic names to the vestiges that remain in modern star catalogues. The researcher then examines the seasonal significance of these Auspicious Asterisms (as-suud) within Arabian culture during the first millennium CE, including the use of rhymed prose that had become attached to four of the ten asterisms to tie their heliacal risings to the meteorological and cultural happenings of Arabian winters. The results of this original research demonstrate the historical significance of these stars names that continue in use today.

  108. Schindler, K., 2022, AAS, 54, 349.02, Remembering Carolyn Shoemaker
    Carolyn Shoemaker was a late comer to astronomy, not entering the field until 1980 when she was 51 years old. Like the famous comet-hunting Caroline of two centuries priorCaroline HerschelShoemaker went into astronomy to support a family member: Herschel with her planet-discovering brother William and Shoemaker with her astrogeology husband Gene. For Carolyn, this came about because she had finished raising the Shoemaker's three children and had free time on her hands, so she asked Gene for suggestions on how to fill it. He was then leading a project using Palomar Observatory's 18-inch Schmidt telescope to search for potentially hazardous asteroids and comets. This work involved photographing segments of the sky and then scanning the resulting films with a stereomicroscope for suspects. Gene suggested Carolyn join the project and she took to it immediately. By the time she finished her career in astronomy, she discovered or co-discovered 32 comets, 377 numbered asteroids, and many more unnumbered ones. Comet-Shoemaker-Levy 9 was her most famous discovery, made in 1993 while teamed with Gene and David Levy. The year after its discovery. this icy body dramatically collided with Jupiter in an event observed by astronomers around the world. This was the first time in recorded history that humans observed two solar system bodies colliding, and it brought the discoverers international recognition. Several years later, Carolyn was severely injured in an automobile accident that saw Gene die. After recovering, Carolyn continued her research for several years and also frequently spoke at star parties and other astronomy events around the world. In August 2021, at the age of 92, this grande dame of astronomy passed away.
  109. Bartlett, J., Trimble, V., Griffin, R., et al., (including Schindler, K.), 2022, AAS, 54, 349.04, Working Group on the Preservation of Astronomical Heritage 2022
    Astronomy has a rich history extending backwards in time for millennia to the oldest recorded observations on cuneiform tablets. In North and South America, records of astronomical activities begin with indigenous archaeoastronomy sites and continue in modern observatories. Archived observations, whether sketched by hand or captured in photographs or recorded on electronic media, document the sky at moments that will never be repeated. Access to such records stretches the baseline of time-domain astronomy backwards qualitatively for centuries and quantitively for about 120 years, greatly exceeding the span of modern electronic records. Unfortunately, rapidly evolving technology can render digital data obsolete and unreadable after only a few years unless precautions are taken to convert the information continuously to the latest format. The tools and instruments used by former astronomers demonstrate how they accomplished their science. Although their technologies and processes may be outdated, their work laid the foundation for our current astronomical endeavors. Those practices and the personal experiences of our predecessors provide insight into how the culture of astronomy has evolved and should inform efforts to improve our profession today. The Working Group on the Preservation of Astronomical Heritage (WGPAH) is charged with ensuring heritage resources remain available to astronomers, historians of astronomy, and all interested individuals.

    Consisting of 14 specialists from 7 disciplines, the WGPAH seeks to establish criteria and priorities for preserving astronomical sites, facilities, instruments, and records. In addition, we work to develop and disseminate the best practices for preservation efforts. In doing so, we advise institutions and teams engaged in or considering preservation projects. We also partner with organizations such as the Historical Astronomy Division (HAD) of the AAS, the International Glass Plates Group, and the recently formed Historic Site Designation Task Force, whose missions overlap with ours. We welcome the participation of everyone.

    To access WGPAH resources, please visit our website (https://aas.org/comms/working-group-preservation-astronomical-heritage-wgpah).

    To contribute to WGPAH discussions and activities, please join our low-volume mailing list (https://lists.aas.org/).

  110. Levine, S., Bartlett, J., Kern, B., et al., 2022, AAS, 54, 349.06, The International Glass Plates Group: Resources for Astronomical Plate Preservation
    The International Glass Plates Group is a recently-formed gathering that includes astronomers, librarians, historians, curators, and others with representation from a host of countries. What has brought us together is our assumed curatorship of collections of astronomical photographic plates and associated records that were once open resources in our respective departments and observatories. Some of the collections reach back a century or more. The Group meets monthly to share information, experiences and ideas, to understand and evaluate the potential of the collections or individual items, and to work out a strategy for moving forward to make these data discoverable, accessible, and usable.

    Each month, an IGPG subgroup presents a topic via Zoom after which discussion ensues. The discussion topics have covered preservation practices; transcribing metadata from observing logbooks and assembling this information in searchable form; digitization methods; building a census of collections; scientific use cases; accessibility of the contents of the collections to external researchers; and much more. We are working to inform ourselves of other relevant efforts, and we are taking advantage of communities with aligned interests. In addition, the Group is planning an in-person, 3-day conference in May 2023. Overall, the Group provides a forum to explore solutions to common problems. This poster describes Group activities to encourage interest by newcomers and to identify opportunities for wider collaborations.

  111. Llama, J., Brewer, J., Zhao, L., et al., 2022, AAS, 54, 401.04, Observing the Sun with the Lowell Observatory Solar Telescope and the EXtreme PREcision Spectrograph
    The signal induced by a temperate, terrestrial planet orbiting a Sun-like star is an order of magnitude smaller than the host stars' intrinsic variability. Understanding stellar activity is, therefore, a fundamental obstacle in confirming the smallest exoplanets

    The EXtreme PREcision Spectrograph (EXPRES) is one of the newest high-resolution spectrographs designed for obtaining EPRV measurements of stars to search for Earth-sized exoplanets. Recently, we integrated a solar feed into EXPRES to observe the Sun during the day in an analogous way to the stars at night. The Lowell Observatory Solar Telescope (LOST) is a 70-mm aperture lens that is fiber-fed into EXPRES. In clear conditions, the EXPRES solar observations have a cadence of approximately 300-s and single measurement uncertainty of just 35 cm/s.

    Since first light in late 2020, we have obtained over 25,000 RV measurements of the Sun. This work will present the first year of data, comparisons with disk-resolved data from NASA's Solar Dynamics Observatory, and prospects for correcting the RV variability induced by stellar activity.

  112. Johns-Krull, C., Prato, L., Stahl, A., et al., (including Tang, S., Llama, J.), 2022, AAS, 54, 406.13, The Magnetic Field Variability of CI Tau and V830 Tau
    Young (~2 Myr), roughly solar mass stars are known to be very magnetically active. These T Tauri stars typically display mean surface magnetic field strengths of 2-2.5 kG. To date, little is known about the variability of the magnetic fields on these stars, though strong photometric variability of weak-lined (diskless, non-accreting) T Tauri stars on rotational timescales indicates that large spots are present on their surface which may then produce magnetic field strength variability on similar timescales. Longer timescale variations in the field may result from the dynamo process that produces the strong fields in the first place. In order to explore the amplitude and timescale of magnetic field variability on T Tauri stars, we analyze time series of high resolution (R ~ 45,000) K band spectra obtained with the IGRINS spectrometer of the weak-lined star V830 Tau and the classical (accreting) T Tauri star CI Tau. Over approximately 4.5 years, we obtained 86 nights of data on V830 Tau and 70 nights of data on CI Tau. These two stars are of particular interest as both are suspected of hosting newly formed hot Jupiters in orbit around them. We use magnetically sensitive Ti I lines in the K band to determine the mean magnetic field on the surface for each night of observation. We then analyze the resulting time series of magnetic field measurements and characterize the field variability on these young stars.
  113. Huls, C., Prato, L., Tang, S., et al., (including Wasserman, L.), 2022, AAS, 54, 406.15, Orbital and Circumstellar Properties of the Pre-Main Sequence Double-Lined Spectroscopic Binary System V562 Ori
    Using high-resolution H-band spectra from the IGRINS spectrograph on the Lowell Discovery Telescope and a two-dimensional cross-correlation technique, we measured the radial velocities, spectral types, v*sin(i) values, and flux ratio for both components in the young binary system V562 Ori. The observed templates that maximized the cross-correlation coefficients for 11 epochs of spectra are BS8085 (K5), for the primary, and HD97101 (K6), for the secondary. We found an orbital period of ~12 days, a mass ratio close to unity, and a low eccentricity for the system. Synthetic stellar spectra also served to determine radial velocities with lower uncertainty than the observed templates; we discuss the consistency between our analysis using both observed and synthetic stellar templates. A lack of near-infrared excess in the system indicates no warm dust in close proximity to the stars; however, 3.6 and 4.5 micron data from the YSOVARS program demonstrate the presence of cool dust likely in a circumbinary disk. Variability in the brightness and color of the mid-infrared excess appears to be correlated with the orbital period. Archival L-band spectra from the NIRSPEC instrument on the Keck II telescope show no evidence for water ice in the circumbinary disk. For all 11 epochs of our IGRINS observations, strong, variable Bracket gamma emission is evident in the K-band region of the spectra; we determined that this feature arises in the local, diffuse warm gas in the Orion region. This research was supported in part by NSF awards AST-1313399 and AST-1518081.
  114. Brewer, J., Zhao, L., Fischer, D., et al., (including Llama, J.), 2022, AAS, 54, 434.02, Revealing the In-Between: Results from the EXPRES 100 Earths Survey
    Statistics from transit surveys indicate that the most common type of planet is one with a radius between that of Earth and Neptune with ~30% of stars hosting one in their inner system; there is no analog of this planet type in the solar system. Radial velocity surveys have been able to characterize some of these planets, but typically only on orbits less than 40 days. We still know little about planetary system architectures at wider orbits and have yet to detect any architectures like the solar system. The 100 Earths Survey using the EXtreme PREcision Spectrometer (EXPRES) on the Lowell Discovery Telescope (LDT) is designed specifically to reveal small planets at close orbits and sub-Neptunes out to four year orbits. The program has been taking high cadence science observations since early 2019. During this time, more than one third of regularly observed systems are showing possible new planetary signals, most in multi-planet systems. I will present our latest results, focusing on one new system with two sub-Neptune mass planets.
  115. Ramiaramanantsoa, T., Shkolnik, E., Bowman, J., et al., (including Llama, J.), 2022, AAS, 54, 436.02, The Star-Planet Activity Research CubeSat (SPARCS)
    The Star-Planet Activity Research CubeSat (SPARCS) is a 6U CubeSat observatory equipped with a 9-cm telescope and a dual-band camera, currently mid-way into its development phase, and expected to be ready for insertion into low-Earth orbit in early 2024. SPARCS is specifically designed to do unprecedented long time baseline photometric monitoring of the flaring and chromospheric activity of a sample of twenty M stars simultaneously in the near-ultraviolet (NUV) and the far-ultraviolet (FUV). The SPARCS observations will considerably improve M star UV flare frequency distributions as they will enable the study of M star UV flares across a much broader range of flare energies than previous short-term observations have done. We will present the current status of the development of the mission, which is currently approaching its critical design review.

    Acknowledgements: Funding for SPARCS is provided by NASA's Astrophysics Research and Analysis (APRA) program.

  116. Mau, S., Nadler, E., Wechsler, R., et al., (including Kuehn, K.), 2022, ApJ, 932, 128, Milky Way Satellite Census. IV. Constraints on Decaying Dark Matter from Observations of Milky Way Satellite Galaxies
    We use a recent census of the Milky Way (MW) satellite galaxy population to constrain the lifetime of particle dark matter (DM). We consider two-body decaying dark matter (DDM) in which a heavy DM particle decays with lifetime comparable to the age of the universe to a lighter DM particle (with mass splitting ) and to a dark radiation species. These decays impart a characteristic "kick velocity," V kick = c, on the DM daughter particles, significantly depleting the DM content of low-mass subhalos and making them more susceptible to tidal disruption. We fit the suppression of the present-day DDM subhalo mass function (SHMF) as a function of and V kick using a suite of high-resolution zoom-in simulations of MW-mass halos, and we validate this model on new DDM simulations of systems specifically chosen to resemble the MW. We implement our DDM SHMF predictions in a forward model that incorporates inhomogeneities in the spatial distribution and detectability of MW satellites and uncertainties in the mapping between galaxies and DM halos, the properties of the MW system, and the disruption of subhalos by the MW disk using an empirical model for the galaxy-halo connection. By comparing to the observed MW satellite population, we conservatively exclude DDM models with < 18 Gyr (29 Gyr) for V kick = 20 kms-1 (40 kms-1) at 95% confidence. These constraints are among the most stringent and robust small-scale structure limits on the DM particle lifetime and strongly disfavor DDM models that have been proposed to alleviate the Hubble and S 8 tensions.
  117. Llama, J., Fischer, D., Brewer, J., et al., 2022, BAAS, 54, 102.102, Observing the Sun with EXPRES and the Lowell Observatory Solar Telescope
    The signal induced by a temperate, terrestrial planet orbiting a Sun-like star is an order of magnitude smaller than the host stars' intrinsic variability. Understanding stellar activity is, therefore, a fundamental obstacle in confirming the smallest exoplanets

    The EXtreme PREcision Spectrograph (EXPRES) is one of the newest high-resolution spectrographs designed for obtaining EPRV measurements of stars to search for Earth-sized exoplanets. Recently, we integrated a solar feed into EXPRES to observe the Sun during the day in an analogous way to the stars at night. The Lowell Observatory Solar Telescope (LOST) is a 70-mm aperture lens that is fiber-fed into EXPRES. In clear conditions, the EXPRES solar observations have a cadence of approximately 300-s and single measurement uncertainty of just 35 cm/s.

    Since first light in late 2020, we have obtained over 25,000 RV measurements of the Sun. This work will present the first year of data, comparisons with disk-resolved data from NASA's Solar Dynamics Observatory, and prospects for correcting the RV variability induced by stellar activity.

  118. Loyd, R., Jin, M., Mason, J., et al., (including Llama, J.), 2022, BAAS, 54, 102.152, How Can We Constrain Stellar Coronal Mass Ejections? A Proof of Concept for Coronal Dimming Using Archival Far Ultraviolet Spectrophotometry of Eridani
    Coronal mass ejections (CMEs), frequent partners to flares, are a regular fact of space weather in the solar system. CMEs may contribute significantly to solar/stellar spin down and, when they impact planets, they perturb atmospheric chemistry and strip mass. The regular flares of other stars strongly suggest regular CMEs, but direct evidence is sparse. On the Sun, a reliable indicator of CMEs is the drop in coronal emission that results directly from the ejection and loss of emitting material, termed "coronal irradiance dimming." Generalizing this diagnostic for use with stellar observations can enable novel constraints on stellar CMEs. We present the results from a search for post-flare coronal dimming on the 400 Myr K2 dwarf Eridani using archival HST spectra. The analysis depends on coronal Fe XII (formed at ~1 MK) and Fe XXI (formed at ~10 MK) emission lines in far-ultraviolet spectra observed by the Cosmic Origins Spectrograph. From two upper limits and one inconclusive dimming event, we find that flare-associated CMEs with masses greater than a few 1015 g, which occur every few days on the Sun, are unlikely to occur more than 10x as frequently on the younger, more active Eridani. These results, based on less than a day of data, demonstrate the potential value of coronal dimming observations for characterizing the space weather environments of stars other than the Sun.
  119. Tang, S., Stahl, A., Prato, L., et al., (including Llama, J.), 2022, BAAS, 54, 102.337, IGRINS RV: A Precision RV Pipeline for IGRINS Using Modified Forward-Modeling in the Near-Infrared and Its Early Science Results
    The best way to understand planet formation is to look for planets still forming; however, searching for exoplanets around pre-main sequence stars using the radial velocity (RV) method is challenging because of the strong stellar activity of the host star. As the RV signal produced by the stellar activity (e.g., cold spots) is reduced in the near-infrared (NIR), having both NIR and optical RV measurements can help confirm a planet's existence. Here we present IGRINS RV, an open-source python package for computing NIR RVs from the Immersion GRating INfrared Spectrometer (IGRINS, currently a guest instrument on Gemini South), a R ~ 45,000 spectrograph with simultaneous coverage of the H band (1.49-1.80 m) and K band (1.96-2.46 m). IGRINS RV is unique in its ability to achieve RV precisions of 30 m/s in both K and H bands without any physical wavelength calibration tools, such as a gas cell or laser frequency comb. Our modified forward modeling technique demonstrates the ability to deliver precision RVs with only telluric templates derived from A0 standard stars observations to provide a source of common-path wavelength calibration. IGRINS RV has successfully recovered planet signals from two main-sequence stars, HD189733 and Boo A. We will show preliminary results on the optical and the NIR RVs variability analysis for about two dozen T Tauri Stars (TTS, young pre-main sequence stars 10 Myr), including 12 classical accreting TTS and 11 weak-line non-accreting TTS. Both show that the amplitudes of their optical RV variations are, in general, larger in general than their NIR RV variations.
  120. Kunovac, V., Triaud, A., 2022, BAAS, 54, 102.413, A miscellany of misalignments for planets transiting cool stars
    The obliquity of a star relative to the orbit of a transiting planet (the spin-orbit angle) has long been interpreted as a relic of the dynamical history of the system and can even provide observational constraints on planetary formation. The current sample of obliquity measurements on giant planets has revealed several intriguing patterns, including more recent ones such as an overdensity of polar orbiting planets that are yet poorly understood. Another pattern is that the spin-orbit angle distribution is stratified by stellar temperature. The prevailing explanation for this dichotomy is that cold stars (Teff < 6100 K) more actively partake in an exchange of angular momentum mediated by tides, which tends to align the spin and orbital angular momenta faster than for planets orbiting hot stars. In such a scenario one would expect the temperature stratification to weaken as the tidal evolution timescales increase, which would be the case for planets more widely separated from their stars. I will present measurements of the obliquities of 13 cool stars hosting transiting giant planets in weaker tidal regimes than previously considered. The measurements are based on spectroscopic transits observed with the HARPS instrument, and we find that five out of 13 systems are consistent with high obliquities. Some of those that are commensurate with low obliquities are likely candidates for disc-driven migration owing to the weak tidal influence. We show that the distribution of obliquities for cool stars at larger orbital separations is more diverse than previously seen, bringing it more in line with those of hot stars. Our results also appear to show a preference for near-polar orbits for the misaligned systems, in support of recently observed patterns. Moreover, we use both archival and new radial velocities from CORALIE and HARPS to better characterise the planetary eccentricities and long-term radial velocity drifts to further constrain the dynamical origins. We detect eccentricities in two systems. Five systems also display statistically significant radial velocity drifts which could indicate previously unseen companions. This work represents the largest single contribution of stellar obliquity measurements of cool stars from spectroscopic transits, and therefore significantly adds to our knowledge on the orbital evolution of close-in exoplanets. Finally, I will present some efforts to extend the stellar obliquity sample to the sub-Neptune regime using the ESPRESSO spectrograph, as well as ongoing efforts using the EXPRES spectrograph on the 4.3-m Lowell Discovery Telescope.
  121. Brewer, J., Zhao, L., Fischer, D., et al., (including Llama, J.), 2022, BAAS, 54, 401.03, Revealing the In-Between: Results from the EXPRES 100 Earths Survey
    Statistics from transit surveys indicate that the most common type of planet is one with a radius between that of Earth and Neptune with ~30% of stars hosting one in their inner system; there is no analog of this planet type in the solar system. Radial velocity surveys have been able to characterize some of these planets, but typically only on orbits less than 40 days. We still know little about planetary system architectures at wider orbits and have yet to detect any architectures like the solar system. The 100 Earths Survey using the EXtreme PREcision Spectrometer (EXPRES) on the Lowell Discovery Telescope (LDT) is designed specifically to reveal small planets at close orbits and sub-Neptunes out to four year orbits. The program has been taking high cadence science observations since early 2019. During this time, more than one third of regularly observed systems are showing possible new planetary signals, most in multi-planet systems. I will present our latest results, focusing on one new system with two sub-Neptune mass planets.
  122. Seligman, D., Rogers, L., Cabot, S., et al., (including Kareta, T.), 2022, BAAS, 54, 405.03, Interstellar Comets and the New Insights to Planet Formation They Provide
    Minor bodies have opened windows into our understanding of the solar system planets' formation and evolution. The Kirkwood gaps in the asteroid belt led to the discovery that seemingly immutable solar system bodies were chaotic, and the discovery of the Kuiper belt led to the realization that the giant planets underwent a transient period of violent instability. The discoveries of the first two interstellar minor bodies, 1I/`Oumuamua and 2I/Borisov, provided a chance to obtain new constraints on the formation location of ejected planetesimals and the occurrence rate and dynamical evolution of extrasolar planets responsible for their ejection. The forthcoming Rubin Observatory Legacy Survey of Space and Time (LSST) should detect 3 interstellar comets every year. We advocate for future measurements of the carbon to oxygen ratio in these comets, which traces formation location within the original protostellar disk. We review similar measurements for solar system comets, which indicate formation interior to the CO snowline. By comparing cometary C/O ratios calculated with various molecular species, we argue that measurements of H2O, CO2 and CO should be prioritized for interstellar comets. We quantify the extent to which these measurements probe the primordial composition of an interstellar comet as a function of age and trajectory, by calculating the relative change in diameter via erosion in the interstellar medium and the Solar System. We estimate that ~60% of 'Oumuamua-like and ~10% of Borisov-like interstellar objects detected by the LSST will exhibit cometary activity representative of the primordial composition. By accounting for uncertainties and scatter in previously measured cometary and stellar C/O ratios, we estimate that these measurements for 5 objects will reveal a formation location interior or exterior to the CO snowline of ejected comets. Based on the anomalously high C/O ratio of 2I/Borisov and C/2016 R2 with respect to typical solar system comets, we argue that comets ejected via giant planet scattering largely form exterior to the CO snowline, while the remnant and bound H2O dominated population formed interior to the CO snowline. We provide an overview of the currently operational and forthcoming facilities capable of producing these measurements which will test this hypothesis and provide key insights into the efficiency of and mechanisms for cometary ejection in exoplanetary systems.
  123. Schleicher, D., 2022, PSJ, 3, 143, Comet 21P/Giacobini-Zinner: Narrowband Photometry of the Prototype of Carbon-chain Depleted Comets at Multiple Apparitions
    We obtained extensive narrowband photoelectric photometry of Comet 21P/Giacobini-Zinner with observations spanning 33 yr. The original data from 1985 were re-reduced and are presented along with data from three additional apparitions, including 2018/19. The original conclusion regarding Giacobini-Zinner's chemical composition remains unchanged, with it having a 4-6 depletion in the carbon-chain molecules C2 and C3 and in NH, as compared with both OH and CN. The comet continues to exhibit a large asymmetry in production rates as a function of time and heliocentric distance, with production reaching a peak 3-5 weeks prior to perihelion. All species, including dust, follow the same general production rate curve each apparition, and the carbon-bearing species are always very similar to one another. However, OH and NH each differ in detail from the carbon-bearing species, implying somewhat varied composition between source regions. Longer term, there are only small secular changes among the apparitions before and near perihelion, but larger changes are evident as the comet recedes from the Sun, suggestive of a progressive precession of the rotation axis.
  124. DeRose, J., Wechsler, R., Becker, M., et al., (including Kuehn, K.), 2022, PhRvD, 105, 123520, Dark Energy Survey Year 3 results: Cosmology from combined galaxy clustering and lensing validation on cosmological simulations
    We present a validation of the Dark Energy Survey Year 3 (DES Y3) 3 2 -point analysis choices by testing them on BUZZARD2.0, a new suite of cosmological simulations that is tailored for the testing and validation of combined galaxy clustering and weak-lensing analyses. We show that the BUZZARD2.0 simulations accurately reproduce many important aspects of the DES Y3 data, including photometric redshift and magnitude distributions, and the relevant set of two-point clustering and weak-lensing statistics. We then show that our model for the 3 2 -point data vector is accurate enough to recover the true cosmology in simulated surveys assuming the true redshift distributions for our source and lens samples, demonstrating robustness to uncertainties in the modeling of the nonlinear matter power spectrum, nonlinear galaxy bias, and higher-order lensing corrections. Additionally, we demonstrate for the first time that our photometric redshift calibration methodology, including information from photometry, spectroscopy, clustering cross-correlations, and galaxy-galaxy lensing ratios, is accurate enough to recover the true cosmology in simulated surveys in the presence of realistic photometric redshift uncertainties.
  125. Pang, X., Tang, S., Li, Y., et al., 2022, ApJ, 931, 156, 3D Morphology of Open Clusters in the Solar Neighborhood with Gaia EDR 3. II. Hierarchical Star Formation Revealed by Spatial and Kinematic Substructures
    We identify members of 65 open clusters in the solar neighborhood using the machine-learning algorithm StarGO based on Gaia EDR3 data. After adding members of 20 clusters from previous studies we obtain 85 clusters, and study their morphology and kinematics. We classify the substructures outside the tidal radius into four categories: filamentary (f1) and fractal (f2) for clusters <100 Myr, and halo (h) and tidal tail (t) for clusters >100 Myr. The kinematical substructures of f1-type clusters are elongated; these resemble the disrupted cluster Group X. Kinematic tails are distinct in t-type clusters, especially Pleiades. We identify 29 hierarchical groups in four young regions (Alessi 20, IC 348, LP 2373, LP 2442); 10 among these are new. The hierarchical groups form filament networks. Two regions (Alessi 20, LP 2373) exhibit global orthogonal expansion (stellar motion perpendicular to the filament), which might cause complete dispersal. Infalling-like flows (stellar motion along the filament) are found in UBC 31 and related hierarchical groups in the IC 348 region. Stellar groups in the LP 2442 region (LP 2442 gp 1-5) are spatially well mixed but kinematically coherent. A merging process might be ongoing in the LP 2442 subgroups. For younger systems (30 Myr), the mean axis ratio, cluster mass, and half-mass-radius tend to increase with age values. These correlations between structural parameters may imply two dynamical processes occurring in the hierarchical formation scenario in young stellar groups: (1) filament dissolution and (2) subgroup mergers.
  126. Aadland, E., Massey, P., Hillier, D., et al., (including Neugent, K.), 2022, ApJ, 931, 157, WO-type Wolf-Rayet Stars: The Last Hurrah of Massive Star Evolution
    Are WO-type Wolf-Rayet (WR) stars in the final stage of massive star evolution before core-collapse? Although WC- and WO-type WRs have very similar spectra, WOs show a much stronger O VI 3811,34 emission-line feature. This has usually been interpreted to mean that WOs are more oxygen rich than WCs, and thus further evolved. However, previous studies have failed to model this line, leaving the relative abundances uncertain, and the relationship between the two types unresolved. To answer this fundamental question, we modeled six WCs and two WOs in the LMC using UV, optical, and NIR spectra with the radiative transfer code CMFGEN in order to determine their physical properties. We find that WOs are not richer in oxygen; rather, the O VI feature is insensitive to the abundance. However, the WOs have a significantly higher carbon and lower helium content than the WCs, and hence are further evolved. A comparison of our results with single-star Geneva and binary BPASS evolutionary models show that, while many properties match, there is more carbon and less oxygen in the WOs than either set of evolutionary model predicts. This discrepancy may be due to the large uncertainty in the 12C+4He 16O nuclear reaction rate; we show that if the Kunz et al. rate is decreased by a factor of 25%-50%, then there would be a good match with the observations. It would also help explain the LIGO/VIRGO detection of black holes whose masses are in the theoretical upper mass gap. * This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.
  127. Akhazhanov, A., More, A., Amini, A., et al., (including Kuehn, K.), 2022, MNRAS, 513, 2407, Finding quadruply imaged quasars with machine learning - I. Methods
    Strongly lensed quadruply imaged quasars (quads) are extraordinary objects. They are very rare in the sky and yet they provide unique information about a wide range of topics, including the expansion history and the composition of the Universe, the distribution of stars and dark matter in galaxies, the host galaxies of quasars, and the stellar initial mass function. Finding them in astronomical images is a classic 'needle in a haystack' problem, as they are outnumbered by other (contaminant) sources by many orders of magnitude. To solve this problem, we develop state-of-the-art deep learning methods and train them on realistic simulated quads based on real images of galaxies taken from the Dark Energy Survey, with realistic source and deflector models, including the chromatic effects of microlensing. The performance of the best methods on a mixture of simulated and real objects is excellent, yielding area under the receiver operating curve in the range of 0.86-0.89. Recall is close to 100 per cent down to total magnitude i ~ 21 indicating high completeness, while precision declines from 85 per cent to 70 per cent in the range i ~ 17-21. The methods are extremely fast: training on 2 million samples takes 20 h on a GPU machine, and 108 multiband cut-outs can be evaluated per GPU-hour. The speed and performance of the method pave the way to apply it to large samples of astronomical sources, bypassing the need for photometric pre-selection that is likely to be a major cause of incompleteness in current samples of known quads.
  128. Craig, M., Crawford, S., Seifert, M., et al., (including Ellsworth Bowers, T.), 2022, zndo, astropy/ccdproc: 2.3.1 -- fixes astropy 5.1 compatibility
    This minor release fixes compatibility with astropy 5.1 and includes a packaging fix from new contributor @astrobatty
  129. Ramiaramanantsoa, T., Bowman, J., Shkolnik, E., et al., (including Llama, J.), 2022, AN, 343, e10068, Timeresolved photometry of the highenergy radiation of M dwarfs with the StarPlanet Activity Research Cubesat
    Know thy star, know thy planet,... especially in the ultraviolet (UV). Over the past decade, that motto has grown from mere wish to necessity in the M dwarf regime, given that the intense and highly variable UV radiation from these stars is suspected of strongly impacting their planets' habitability and atmospheric loss. This has led to the development of the Star-Planet Activity Research CubeSat (SPARCS), a NASA-funded 6U CubeSat observatory fully devoted to the photometric monitoring of the UV flaring of M dwarfs hosting potentially habitable planets. The SPARCS science imaging system uses a 9-cm telescope that feeds two delta-doped UV-optimized CCDs through a dichroic beam splitter, enabling simultaneous monitoring of a target field in the near-UV and far-UV. A dedicated onboard payload processor manages science observations and performs near-real time image processing to sustain an autonomous dynamic exposure control algorithm needed to mitigate pixel saturation during flaring events. The mission is currently half-way into its development phase. We present an overview of the mission's science drivers and its expected contribution to our understanding of star-planet interactions. We also present the expected performance of the autonomous dynamic exposure control algorithm, a first-of-its-kind on board a space-based stellar astrophysics observatory.
  130. Secco, L., Jarvis, M., Jain, B., et al., (including Kuehn, K.), 2022, PhRvD, 105, 103537, Dark Energy Survey Year 3 Results: Three-point shear correlations and mass aperture moments
    We present high signal-to-noise measurements of three-point shear correlations and the third moment of the mass aperture statistic using the first 3 years of data from the Dark Energy Survey. We additionally obtain the first measurements of the configuration and scale dependence of the four three-point shear correlations which carry cosmological information. With the third-order mass aperture statistic, we present tomographic measurements over angular scales of 4 to 60 arcminutes with a combined statistical significance of 15.0 . Using the tomographic information and measuring also the second-order mass aperture, we additionally obtain a skewness parameter and its redshift evolution. We find that the amplitudes and scale-dependence of these shear 3pt functions are in qualitative agreement with measurements in a mock galaxy catalog based on N-body simulations, indicating promise for including them in future cosmological analyses. We validate our measurements by showing that B-modes, parity-violating contributions and PSF modeling uncertainties are negligible, and determine that the measured signals are likely to be of astrophysical and gravitational origin.
  131. Bird, M., Linscott, I., Tyler, G., et al., (including Grundy, W.), 2022, PSJ, 3, 109, Detection of Radio Thermal Emission from the Kuiper Belt Object (486958) Arrokoth during the New Horizons Encounter
    The New Horizons spacecraft encountered the Kuiper Belt object (KBO) Arrokoth (486958), originally designated as 2014 MU69 and formerly called "Ultima Thule," on 2019 January 01. At 43.3 au from the Sun and 44.4 au from Earth, this was the most distant spacecraft reconnaissance of a solar system body to date. The Radio Science Experiment (REX) on New Horizons performed radiometry measurements of the KBO's thermal emission at = 4.2 cm in two observation slots, one before (dayside) and one after (nightside) the point of closest approach. Owing to the small size of the target, the intensity of the thermal emission was expected to be only marginally detectable. The KBO was not detected on approach because of unexpectedly large variations in the REX system temperature. A brightness temperature T b = 29 5 K was derived for the nightside observation, considerably less than the predicted equilibrium temperature of ~50 K derived for Arrokoth on the dayside. A model explaining this day-night contrast is used to constrain the global values of emissivity, thermal inertia, and electrical skin depth of the KBO. In particular, models with small values of thermal inertia and small values of electrical skin depth are excluded. Relatively high values of the effective radio emissivity (E eff > 0.8) provide better agreement with the REX observation.
  132. Umurhan, O., Grundy, W., Bird, M., et al., 2022, PSJ, 3, 110, A Near-surface Temperature Model of Arrokoth
    A near-surface thermal model for Arrokoth is developed based on the recently released 105 facet model of the body. This thermal solution takes into account Arrokoth's surface reradiation back onto itself. The solution method exploits Arrokoth's periodic orbital character to develop a thermal response using a time-asymptotic solution method, which involves a Fourier transform solution of the heat equation, an approach recently used by others. We display detailed thermal solutions assuming that Arrokoth's near-surface material's thermal inertia ${ \mathcal I }\,=\,$ 2.5 W/m-2 K-1 s1/2. We predict that at New Horizons' encounter with Arrokoth, its encounter hemisphere surface temperatures were ~57-59 K in its polar regions, 30-40 K in its equatorial zones, and 11-13 K for its winter hemisphere. Arrokoth's orbitally averaged temperatures are around 30-35 K in its polar regions and closer to 40 K near its equatorial zones. Thermal reradiation from the surrounding surface amounts to less than 5% of the total energy budget, while the total energy ensconced into and exhumed out of Arrokoth's interior via thermal conduction over one orbit is about 0.5% of the total energy budget. As a generalized application of this thermal modeling together with other Kuiper Belt object origins considerations, we favor the interpretation that New Horizons' REX instrument's 29 5 K brightness temperature measurement is consistent with Arrokoth's near-surface material being made of sub-to-few-millimeter-size tholin-coated amorphous H2O ice grains with 1 W/m-2 K-1 s1/2 $\lt \,{ \mathcal I }\,\lt $ 10-20 W/m-2 K-1 s1/2 and which are characterized by an X-band emissivity in the range 0.9 and 1.
  133. Lisse, C., Gladstone, G., Young, L., et al., (including Grundy, W.), 2022, PSJ, 3, 112, A Predicted Dearth of Majority Hypervolatile Ices in Oort Cloud Comets
    We present new, ice species-specific New Horizons/Alice upper gas coma production limits from the 2019 January 1 MU69/Arrokoth flyby of Gladstone et al. and use them to make predictions about the rarity of majority hypervolatile (CO, N2, CH4) ices in Kuiper Belt objects and Oort Cloud comets. These predictions have a number of important implications for the study of the Oort Cloud, including the determination of hypervolatile-rich comets as the first objects emplaced into the Oort Cloud, the measurement of CO/N2/CH4 abundance ratios in the protoplanetary disk from hypervolatile-rich comets, and population statistical constraints on early (<20 Myr) planetary aggregation driven versus later (>50 Myr) planetary migration driven emplacement of objects into the Oort Cloud. They imply that the phenomenon of ultradistant active comets like C/2017K2 should be rare, and thus not a general characteristic of all comets. They also suggest that interstellar object 2I/Borisov may not have originated in a planetary system that was inordinately CO rich, but rather could have been ejected onto an interstellar trajectory very early in its natal system's history.
  134. Kareta, T., Reddy, V., Sanchez, J., et al., 2022, PSJ, 3, 105, Near-infrared Spectroscopy of the Nucleus of Low-activity Comet P/2016 BA14 during Its 2016 Close Approach
    The near-Earth comet P/2016 BA14 (PanSTARRS) is a slow-rotating, nearly dormant object, a likely dynamical twin of 252P/LINEAR, and was recently shown to have a mid-infrared spectrum very dissimilar to other comets. Comet BA14 was also recently selected as one of the backup targets for the ESA's Comet Interceptor, so a clearer understanding of BA14's modern properties would not just improve our understanding of how comets go dormant but could also aid in planning for a potential spacecraft visit. We present observations of BA14 during its 2016 Earth close approach taken with the NASA Infrared Telescope Facility on two dates, both of which are consistent with direct observations of its nucleus. The reflectance spectrum of BA14 is similar to 67P/Churyumov-Gerasimenko, albeit highly phase-reddened. Thermal emission contaminates the reflectance spectrum at longer wavelengths, which we correct with a new Markov Chain Monte Carlo thermal modeling code. The models suggest that BA14's visible geometric albedo is p V = 0.01-0.03, consistent with radar observations; its beaming parameter is typical for NEOs observed in its geometry; and its reflectance spectrum is red and linear throughout the H and K bands. It appears very much like a "normal" comet nucleus despite its mid-infrared oddities. A slow loss of fine grains as the object's activity diminished might help to reconcile some of the lines of evidence, and we discuss other possibilities. A spacecraft flyby past BA14 could get closer to the nucleus than with a more active target, and we highlight some science questions that could be addressed with a visit to a (nearly) dormant comet.
  135. Clark, C., van Belle, G., Ciardi, D., et al., 2022, AJ, 163, 232, A Dearth of Close-in Stellar Companions to M-dwarf TESS Objects of Interest
    TESS has proven to be a powerful resource for finding planets, including those that orbit the most prevalent stars in our galaxy: M dwarfs. Identification of stellar companions (both bound and unbound) has become a standard component of the transiting planet confirmation process in order to assess the level of light-curve dilution and the possibility of the target being a false positive. Studies of stellar companions have also enabled investigations into stellar multiplicity in planet-hosting systems, which has wide-ranging implications for both exoplanet detection and characterization, as well as for the formation and evolution of planetary systems. Speckle and AO imaging are some of the most efficient and effective tools for revealing close-in stellar companions; we therefore present observations of 58 M-dwarf TOIs obtained using a suite of speckle imagers at the 3.5 m WIYN telescope, the 4.3 m Lowell Discovery Telescope, and the 8.1 m Gemini North and South telescopes. These observations, as well as near-infrared adaptive optics images obtained for a subset (14) of these TOIs, revealed only two close-in stellar companions. Upon surveying the literature, and cross-matching our sample with Gaia, SUPERWIDE, and the catalog from El-Badry et al., we reveal an additional 15 widely separated common proper motion companions. We also evaluate the potential for undetected close-in companions. Taking into consideration the sensitivity of the observations, our findings suggest that the orbital period distribution of stellar companions to planet-hosting M dwarfs is shifted to longer periods compared to the expected distribution for field M dwarfs.
  136. Strugarek, A., Fares, R., Bourrier, V., et al., (including Llama, J.), 2022, MNRAS, 512, 4556, MOVES - V. Modelling star-planet magnetic interactions of HD 189733
    Magnetic interactions between stars and close-in planets may lead to a detectable signal on the stellar disc. HD 189733 is one of the key exosystems thought to harbour magnetic interactions, which may have been detected in 2013 August. We present a set of 12 wind models at that period, covering the possible coronal states and coronal topologies of HD 189733 at that time. We assess the power available for the magnetic interaction and predict its temporal modulation. By comparing the predicted signal with the observed signal, we find that some models could be compatible with an interpretation based on star-planet magnetic interactions. We also find that the observed signal can be explained only with a stretch-and-break interaction mechanism, while that the Alfven wings scenario cannot deliver enough power. We finally demonstrate that the past observational cadence of HD 189733 leads to a detection rate of only between 12 and 23 per cent, which could explain why star-planet interactions have been hard to detect in past campaigns. We conclude that the firm confirmation of their detection will require dedicated spectroscopic observations covering densely the orbital and rotation period, combined with scarcer spectropolarimetric observations to assess the concomitant large-scale magnetic topology of the star.
  137. Prochaska, J., Hennawi, J., Cooke, R., et al., (including Ellsworth Bowers, T.), 2022, zndo, pypeit/PypeIt: Version 1.8.1
    Minor release. Changes include: Various hotfixes Include preliminary support for fluxing with archived SensFunc files for DEIMOS.
  138. Cordero, J., Harrison, I., Rollins, R., et al., (including Kuehn, K.), 2022, MNRAS, 511, 2170, Dark Energy Survey Year 3 results: marginalization over redshift distribution uncertainties using ranking of discrete realizations
    Cosmological information from weak lensing surveys is maximized by sorting source galaxies into tomographic redshift subsamples. Any uncertainties on these redshift distributions must be correctly propagated into the cosmological results. We present HYPERRANK, a new method for marginalizing over redshift distribution uncertainties, using discrete samples from the space of all possible redshift distributions, improving over simple parametrized models. In HYPERRANK, the set of proposed redshift distributions is ranked according to a small (between one and four) number of summary values, which are then sampled, along with other nuisance parameters and cosmological parameters in the Monte Carlo chain used for inference. This approach can be regarded as a general method for marginalizing over discrete realizations of data vector variation with nuisance parameters, which can consequently be sampled separately from the main parameters of interest, allowing for increased computational efficiency. We focus on the case of weak lensing cosmic shear analyses and demonstrate our method using simulations made for the Dark Energy Survey (DES). We show that the method can correctly and efficiently marginalize over a wide range of models for the redshift distribution uncertainty. Finally, we compare HYPERRANK to the common mean-shifting method of marginalizing over redshift uncertainty, validating that this simpler model is sufficient for use in the DES Year 3 cosmology results presented in companion papers.
  139. Prat, J., Blazek, J., Sanchez, C., et al., (including Kuehn, K., DES Collaboration), 2022, PhRvD, 105, 083528, Dark energy survey year 3 results: High-precision measurement and modeling of galaxy-galaxy lensing
    We present and characterize the galaxy-galaxy lensing signal measured using the first three years of data from the Dark Energy Survey (DES Y3) covering 4132 deg2 . These galaxy-galaxy measurements are used in the DES Y3 3 2 pt cosmological analysis, which combines weak lensing and galaxy clustering information. We use two lens samples: a magnitude-limited sample and the redMaGiC sample, which span the redshift range 0.2 - 1 with 10.7 and 2.6 M galaxies, respectively. For the source catalog, we use the METACALIBRATION shape sample, consisting of 100 M galaxies separated into four tomographic bins. Our galaxy-galaxy lensing estimator is the mean tangential shear, for which we obtain a total SNR of 148 for MagLim (120 for redMaGiC), and 67 (55 ) after applying the scale cuts of 6 Mpc /h . Thus we reach percent-level statistical precision, which requires that our modeling and systematic-error control be of comparable accuracy. The tangential shear model used in the 3 2 pt cosmological analysis includes lens magnification, a five-parameter intrinsic alignment model, marginalization over a point mass to remove information from small scales and a linear galaxy bias model validated with higher-order terms. We explore the impact of these choices on the tangential shear observable and study the significance of effects not included in our model, such as reduced shear, source magnification, and source clustering. We also test the robustness of our measurements to various observational and systematics effects, such as the impact of observing conditions, lens-source clustering, random-point subtraction, scale-dependent METACALIBRATION responses, point spread function residuals, and B modes.
  140. Sanchez, C., Prat, J., Zacharegkas, G., et al., (including Kuehn, K., DES Collaboration), 2022, PhRvD, 105, 083529, Dark Energy Survey Year 3 results: Exploiting small-scale information with lensing shear ratios
    Using the first three years of data from the Dark Energy Survey (DES), we use ratios of small-scale galaxy-galaxy lensing measurements around the same lens sample to constrain source redshift uncertainties, intrinsic alignments and other systematics or nuisance parameters of our model. Instead of using a simple geometric approach for the ratios as has been done in the past, we use the full modeling of the galaxy-galaxy lensing measurements, including the corresponding integration over the power spectrum and the contributions from intrinsic alignments and lens magnification. We perform extensive testing of the small-scale shear-ratio (SR) modeling by studying the impact of different effects such as the inclusion of baryonic physics, nonlinear biasing, halo occupation distribution descriptions and lens magnification, among others, and using realistic N -body simulations of the DES data. We validate the robustness of our constraints in the data by using two independent lens samples with different galaxy properties, and by deriving constraints using the corresponding large-scale ratios for which the modeling is simpler. The results applied to the DES Y3 data demonstrate how the ratios provide significant improvements in constraining power for several nuisance parameters in our model, especially on source redshift calibration and intrinsic alignments. For source redshifts, SR improves the constraints from the prior by up to 38% in some redshift bins. Such improvements, and especially the constraints it provides on intrinsic alignments, translate to tighter cosmological constraints when shear ratios are combined with cosmic shear and other 2pt functions. In particular, for the DES Y3 data, SR improves S8 constraints from cosmic shear by up to 31%, and for the full combination of probes (3 2 pt ) by up to 10%. The shear ratios presented in this work are used as an additional likelihood for cosmic shear, 2 2 pt and the full 3 2 pt in the fiducial DES Y3 cosmological analysis.
  141. Tucker, D., Wiesner, M., Allam, S., et al., (including Kuehn, K.), 2022, ApJ, 929, 115, SOAR/Goodman Spectroscopic Assessment of Candidate Counterparts of the LIGO/Virgo Event GW190814
    On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star-black hole merger (NSBH), the first ever identified. An extensive search for an optical counterpart of this event, designated GW190814, was undertaken using the Dark Energy Camera on the 4 m Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory. Target of Opportunity interrupts were issued on eight separate nights to observe 11 candidates using the 4.1 m Southern Astrophysical Research (SOAR) telescope's Goodman High Throughput Spectrograph in order to assess whether any of these transients was likely to be an optical counterpart of the possible NSBH merger. Here, we describe the process of observing with SOAR, the analysis of our spectra, our spectroscopic typing methodology, and our resultant conclusion that none of the candidates corresponded to the gravitational wave merger event but were all instead other transients. Finally, we describe the lessons learned from this effort. Application of these lessons will be critical for a successful community spectroscopic follow-up program for LVC observing run 4 (O4) and beyond. *Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (MCTIC) do Brasil, the US National Science Foundations National Optical-Infrared Astronomy Research Laboratory (NOIRLab), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).
  142. Lierle, P., Schmidt, C., Baumgardner, J., et al., (including Bida, T.), 2022, PSJ, 3, 87, The Spatial Distribution and Temperature of Mercury's Potassium Exosphere
    Aside from the well-studied sodium doublet, the potassium D lines are the only optical emissions in Mercury's exosphere that are amply bright to contrast with the dayside disk. Measurements of the K exosphere are limited compared to Na, but the K regolith abundance is better constrained, so new insights may help to understand surface-exosphere coupling. We use imaging spectroscopy to map the K brightness over Mercury's evening hemisphere, which shows an enhancement at low to midlatitudes, well equatorward of the Na peak. Both Na and K are brighter in the south, but the ratio between northern and southern hemisphere K emission appears less symmetric than that of Na. The disk-averaged Na/K column density ratio is between 70 and 130. During the same night, the dayside emission was mapped, we used a high-resolution spectrograph to attempt to resolve the Na and K line widths on the nightside. Forward-modeling the alkaline line profiles with hyperfine structure gives Na D1 and D2 line widths of 1114 50 K and 1211 45 K, respectively. D2 may appear hotter solely because its higher opacity adds preferentially to the profile wings. The K line width is surprisingly cold and cannot be easily distinguished from the instrumental line width, even at R = 137,500. Line widths roughly constrain K gas between the surface temperature and 1000 K, making it the coldest metallic constituent of Mercury's exosphere. Although Na and K are chemical analogs and often assumed to have similar properties, the results herein illustrate quite different characteristics between these elements in Mercury's exosphere.
  143. Elmegreen, B., Martinez, Z., Hunter, D., 2022, ApJ, 928, 143, A Search for Correlations between Turbulence and Star Formation in THINGS Galaxies
    The spatial range for feedback from star formation varies from molecular cloud disruption on parsec scales to supershells and disk blowout on kiloparsec scales. The relative amounts of energy and momentum given to these scales are important for understanding the termination of star formation in any one region and the origin of interstellar turbulence and disk stability in galaxies as a whole. Here, we measure, for 11 THINGS galaxies, the excess kinetic energy, velocity dispersion, and surface density of H I gas associated with regions of excess star formation, where the excess is determined from the difference between the observed local value and the azimuthal average. We find small decreases in the excess kinetic energy and velocity dispersion in regions of excess star formation rate density, suggesting that most of the feedback energy does not go into local H I motion. Most likely, it disrupts molecular clouds and dissipates rapidly at high gas density. Some could also be distributed over larger regions, filling in spaces between the peaks of star formation and contributing to other energy sources from self-gravity and spiral arm shocks.
  144. Marsset, M., DeMeo, F., Burt, B., et al., (including Moskovitz, N.), 2022, AJ, 163, 165, The Debiased Compositional Distribution of MITHNEOS: Global Match between the Near-Earth and Main-belt Asteroid Populations, and Excess of D-type Near-Earth Objects
    We report 491 new near-infrared spectroscopic measurements of 420 near-Earth objects (NEOs) collected on the NASA InfraRed Telescope Facility as part of the MIT-Hawaii NEO Spectroscopic Survey. These measurements were combined with previously published data from Binzel et al. and bias-corrected to derive the intrinsic compositional distribution of the overall NEO population, as well as of subpopulations coming from various escape routes (ERs) in the asteroid belt and beyond. The resulting distributions reflect well the overall compositional gradient of the asteroid belt, with decreasing fractions of silicate-rich (S- and Q-type) bodies and increasing fractions of carbonaceous (B-, C-, D- and P-type) bodies as a function of increasing ER distance from the Sun. The close compositional match between NEOs and their predicted source populations validates dynamical models used to identify ERs and argues against any strong composition change with size in the asteroid belt between ~5 km and ~100 m. A notable exception comes from the overabundance of D-type NEOs from the 5:2J and, to a lesser extend, the 3:1J and 6 ERs, hinting at the presence of a large population of small D-type asteroids in the main belt. Alternatively, this excess may indicate preferential spectral evolution from D-type surfaces to C and P types as a consequence of space weathering, or point to the fact that D-type objects fragment more often than other spectral types in the NEO space. No further evidence for the existence of collisional families in the main belt, below the detection limit of current main-belt surveys, was found in this work.
  145. Zhao, L., Fischer, D., Ford, E., et al., (including Llama, J.), 2022, AJ, 163, 171, The EXPRES Stellar Signals Project II. State of the Field in Disentangling Photospheric Velocities
    Measured spectral shifts due to intrinsic stellar variability (e.g., pulsations, granulation) and activity (e.g., spots, plages) are the largest source of error for extreme-precision radial-velocity (EPRV) exoplanet detection. Several methods are designed to disentangle stellar signals from true center-of-mass shifts due to planets. The Extreme-precision Spectrograph (EXPRES) Stellar Signals Project (ESSP) presents a self-consistent comparison of 22 different methods tested on the same extreme-precision spectroscopic data from EXPRES. Methods derived new activity indicators, constructed models for mapping an indicator to the needed radial-velocity (RV) correction, or separated out shape- and shift-driven RV components. Since no ground truth is known when using real data, relative method performance is assessed using the total and nightly scatter of returned RVs and agreement between the results of different methods. Nearly all submitted methods return a lower RV rms than classic linear decorrelation, but no method is yet consistently reducing the RV rms to sub-meter-per-second levels. There is a concerning lack of agreement between the RVs returned by different methods. These results suggest that continued progress in this field necessitates increased interpretability of methods, high-cadence data to capture stellar signals at all timescales, and continued tests like the ESSP using consistent data sets with more advanced metrics for method performance. Future comparisons should make use of various well-characterized data sets-such as solar data or data with known injected planetary and/or stellar signals-to better understand method performance and whether planetary signals are preserved.
  146. Somboonpanyakul, T., McDonald, M., Noble, A., et al., (including Kuehn, K.), 2022, AJ, 163, 146, The Evolution of AGN Activity in Brightest Cluster Galaxies
    We present the results of an analysis of Wide-field Infrared Survey Explorer (WISE) observations of the full 2500 deg2 South Pole Telescope (SPT)-Sunyaev-Zel'dovich cluster sample. We describe a process for identifying active galactic nuclei (AGN) in brightest cluster galaxies (BCGs) based on WISE mid-IR color and redshift. Applying this technique to the BCGs of the SPT-SZ sample, we calculate the AGN-hosting BCG fraction, which is defined as the fraction of BCGs hosting bright central AGNs over all possible BCGs. Assuming an evolving single-burst stellar population model, we find statistically significant evidence (>99.9%) for a mid-IR excess at high redshift compared to low redshift, suggesting that the fraction of AGN-hosting BCGs increases with redshift over the range of 0 < z < 1.3. The best-fit redshift trend of the AGN-hosting BCG fraction has the form (1 + z)4.11.0. These results are consistent with previous studies in galaxy clusters as well as as in field galaxies. One way to explain this result is that member galaxies at high redshift tend to have more cold gas. While BCGs in nearby galaxy clusters grow mostly by dry mergers with cluster members, leading to no increase in AGN activity, BCGs at high redshift could primarily merge with gas-rich satellites, providing fuel for feeding AGNs. If this observed increase in AGN activity is linked to gas-rich mergers rather than ICM cooling, we would expect to see an increase in scatter in the P cav versus L cool relation at z > 1. Last, this work confirms that the runaway cooling phase, as predicted by the classical cooling-flow model, in the Phoenix cluster is extremely rare and most BCGs have low (relative to Eddington) black hole accretion rates.
  147. Mann, A., Wood, M., Schmidt, S., et al., (including Llama, J., Prato, L., Tang, S.), 2022, AJ, 163, 156, TESS Hunt for Young and Maturing Exoplanets (THYME). VI. An 11 Myr Giant Planet Transiting a Very-low-mass Star in Lower Centaurus Crux
    Mature super-Earths and sub-Neptunes are predicted to be Jovian radius when younger than 10 Myr. Thus, we expect to find 5-15 R planets around young stars even if their older counterparts harbor none. We report the discovery and validation of TOI 1227b, a 0.85 0.05 R J (9.5 R ) planet transiting a very-low-mass star (0.170 0.015 M ) every 27.4 days. TOI 1227's kinematics and strong lithium absorption confirm that it is a member of a previously discovered subgroup in the Lower Centaurus Crux OB association, which we designate the Musca group. We derive an age of 11 2 Myr for Musca, based on lithium, rotation, and the color-magnitude diagram of Musca members. The TESS data and ground-based follow-up show a deep (2.5%) transit. We use multiwavelength transit observations and radial velocities from the IGRINS spectrograph to validate the signal as planetary in nature, and we obtain an upper limit on the planet mass of 0.5 M J. Because such large planets are exceptionally rare around mature low-mass stars, we suggest that TOI 1227b is still contracting and will eventually turn into one of the more common <5 R planets.
  148. Rodriguez-Monroy, M., Weaverdyck, N., Elvin-Poole, J., et al., (including Kuehn, K.), 2022, MNRAS, 511, 2665, Dark Energy Survey Year 3 results: galaxy clustering and systematics treatment for lens galaxy samples
    In this work, we present the galaxy clustering measurements of the two DES lens galaxy samples: a magnitude-limited sample optimized for the measurement of cosmological parameters, MAGLIM, and a sample of luminous red galaxies selected with the REDMAGIC algorithm. MAGLIM/REDMAGIC sample contains over 10 million/2.5 million galaxies and is divided into six/five photometric redshift bins spanning the range z [0.20, 1.05]/z [0.15, 0.90]. Both samples cover 4143 $\deg ^2$ over which we perform our analysis blind, measuring the angular correlation function with an S/N ~ 63 for both samples. In a companion paper, these measurements of galaxy clustering are combined with the correlation functions of cosmic shear and galaxy-galaxy lensing of each sample to place cosmological constraints with a 3 2pt analysis. We conduct a thorough study of the mitigation of systematic effects caused by the spatially varying survey properties and we correct the measurements to remove artificial clustering signals. We employ several decontamination methods with different configurations to ensure the robustness of our corrections and to determine the systematic uncertainty that needs to be considered for the final cosmology analyses. We validate our fiducial methodology using lognormal mocks, showing that our decontamination procedure induces biases no greater than 0.5 in the (m, b) plane, where b is the galaxy bias.
  149. Zurcher, D., Fluri, J., Sgier, R., et al., (including Kuehn, K.), 2022, MNRAS, 511, 2075, Dark energy survey year 3 results: Cosmology with peaks using an emulator approach
    We constrain the matter density m and the amplitude of density fluctuations 8 within the CDM cosmological model with shear peak statistics and angular convergence power spectra using mass maps constructed from the first three years of data of the Dark Energy Survey (DES Y3). We use tomographic shear peak statistics, including cross-peaks: peak counts calculated on maps created by taking a harmonic space product of the convergence of two tomographic redshift bins. Our analysis follows a forward-modelling scheme to create a likelihood of these statistics using N-body simulations, using a Gaussian process emulator. We take into account the uncertainty from the remaining, largely unconstrained CDM parameters (b, ns, and h). We include the following lensing systematics: multiplicative shear bias, photometric redshift uncertainty, and galaxy intrinsic alignment. Stringent scale cuts are applied to avoid biases from unmodelled baryonic physics. We find that the additional non-Gaussian information leads to a tightening of the constraints on the structure growth parameter yielding $S_8~\equiv ~\sigma _8\sqrt{\Omega _{\mathrm{m}}/0.3}~=~0.797_{-0.013}^{+0.015}$ (68 per cent confidence limits), with a precision of 1.8 per cent, an improvement of 38 per cent compared to the angular power spectra only case. The results obtained with the angular power spectra and peak counts are found to be in agreement with each other and no significant difference in S8 is recorded. We find a mild tension of $1.5 \, \sigma$ between our study and the results from Planck 2018, with our analysis yielding a lower S8. Furthermore, we observe that the combination of angular power spectra and tomographic peak counts breaks the degeneracy between galaxy intrinsic alignment AIA and S8, improving cosmological constraints. We run a suite of tests concluding that our results are robust and consistent with the results from other studies using DES Y3 data.
  150. Claytor, Z., van Saders, J., Llama, J., et al., 2022, ApJ, 927, 219, Recovery of TESS Stellar Rotation Periods Using Deep Learning
    We used a convolutional neural network to infer stellar rotation periods from a set of synthetic light curves simulated with realistic spot-evolution patterns. We convolved these simulated light curves with real TESS light curves containing minimal intrinsic astrophysical variability to allow the network to learn TESS systematics and estimate rotation periods despite them. In addition to periods, we predict uncertainties via heteroskedastic regression to estimate the credibility of the period predictions. In the most credible half of the test data, we recover 10% accurate periods for 46% of the targets, and 20% accurate periods for 69% of the targets. Using our trained network, we successfully recover periods of real stars with literature rotation measurements, even past the 13.7 day limit generally encountered by TESS rotation searches using conventional period-finding techniques. Our method also demonstrates resistance to half-period aliases. We present the neural network and simulated training data, and introduce the software butterpy used to synthesize the light curves using realistic starspot evolution.
  151. Schambeau, C., McKay, A., Fernandez, Y., et al., (including Kareta, T.), 2022, hst, 16921, Enabling a First in a Lifetime Multi-Wavelength Gas and Dust Coma Characterization of the Centaur 39P/Oterma
    Centaurs are the dynamical intermediary between the more distant and thermally pristine Trans-Neptunian Objects (TNOs) with the more processed and active Jupiter-Family Comets (JFCs). In the Centaur region between Neptune and Jupiter the thermal activation of many cosmogonically abundant volatile species occurs driving comae activity. Investigations of these distant comae provide salient data to test models of the solar system's formation. To date thorough Centaur gas comae characterizations are prohibitive due to instrumental sensitivity limitations, however the newly launched James Webb Space Telescope (JWST) will provide the sensitivities necessary to probe Centaur gas comae. Six Centaurs have been approved for JWST Cycle 1 gas comae characterizations [McKay et al. 2021] with additional contemporaneously acquired dust comae observations from other observatories. Of the six JWST Centaur targets 39P/Oterma is predicted to be beyond suitable characterization through ground-based assets during the Cycle 1 NIRSpec observations. We request 2 HST orbits during Cycle 29 (Jul. - Aug. 2022) of WFC3-UVIS imaging to contemporaneously characterize the dust coma of the Centaur 39P/Oterma during scheduled Cycle 1 JWST NIRSpec gas coma characterization. The tight, stable, and well characterized WFC3 PSF in combination with HST's sensitivity to low surface brightness provide the only observational platform currently available to detect and isolate the flux from 39P's dust coma from its nucleus contribution. If a suitable ramp up of comae activity occurs before the scheduled JWST observations we will forgo the HST observations, instead utilizing ground-based assets.
  152. Smith, E., Logsdon, S., McLean, I., et al., (including Hamilton, R.), 2022, irbf, 32, PAHs Near and Far: Ground and Airborne 3-5 micron observations of PAHs in Planetary Nebulae and Star Forming Regions in the Era of JWST
    Polycyclic Aromatic Hydrocarbons (PAHs) exhibit bright, broad emission features throughout the infrared with main features at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 m. These bands arise from the UV excitation of PAHs and relaxation through the vibration, bending and/or stretching of the CH and CC bonds. This emission has been observed in multiple astronomical phenomena, including planetary nebulae, where they are believed to be formed, and star-forming regions, which has led to their use as a marker for estimating star formation rates in distant galaxies. Many of these bands are accessible from ground-based observatories, including 3.3 micron PAH feature and its associated aliphatic features at 3.4-3.6 microns. We used ground-based (Lick/FLITECAM and Keck/NIRSPEC) observations of the ~3-5 micron spectra of young planetary nebulae and nearby star-forming regions, to investigate the spatial distribution and spectral variation of PAH emission, and stratospheric (SOFIA/FLITECAM) observations to constrain the theoretical contribution of the 4.4-4.8 micron deuterated-PAH features and the weak 5.25 PAH emission feature. Studying young PNs and nearby star-forming regions with ground-based telescopes gives a unique opportunity for fully understanding PAH emission, processing and variation that can be used in interpreting the extra-galactic PAH spectra JWST will study.
  153. Singer, K., White, O., Schmitt, B., et al., (including Grundy, W.), 2022, NatCo, 13, 1542, Large-scale cryovolcanic resurfacing on Pluto
    The New Horizons spacecraft returned images and compositional data showing that terrains on Pluto span a variety of ages, ranging from relatively ancient, heavily cratered areas to very young surfaces with few-to-no impact craters. One of the regions with very few impact craters is dominated by enormous rises with hummocky flanks. Similar features do not exist anywhere else in the imaged solar system. Here we analyze the geomorphology and composition of the features and conclude this region was resurfaced by cryovolcanic processes, of a type and scale so far unique to Pluto. Creation of this terrain requires multiple eruption sites and a large volume of material (>104 km3) to form what we propose are multiple, several-km-high domes, some of which merge to form more complex planforms. The existence of these massive features suggests Pluto's interior structure and evolution allows for either enhanced retention of heat or more heat overall than was anticipated before New Horizons, which permitted mobilization of water-ice-rich materials late in Pluto's history.
  154. Golden-Marx, J., Miller, C., Zhang, Y., et al., (including Kuehn, K.), 2022, ApJ, 928, 28, The Observed Evolution of the Stellar Mass-Halo Mass Relation for Brightest Central Galaxies
    We quantify evolution in the cluster-scale stellar mass-halo mass (SMHM) relation's parameters using 2323 clusters and brightest central galaxies (BCGs) over the redshift range 0.03 z 0.60. The precision on the inferred SMHM parameters is improved by including the magnitude gap (m gap) between the BCG and fourth-brightest cluster member (M14) as a third parameter in the SMHM relation. At fixed halo mass, accounting for m gap, through a stretch parameter, reduces the SMHM relation's intrinsic scatter. To explore this redshift range, we use clusters, BCGs, and cluster members identified using the Sloan Digital Sky Survey C4 and redMaPPer cluster catalogs and the Dark Energy Survey redMaPPer catalog. Through this joint analysis, we detect no systematic differences in BCG stellar mass, m gap, and cluster mass (inferred from richness) between the data sets. We utilize the Pareto function to quantify each parameter's evolution. We confirm prior findings of negative evolution in the SMHM relation's slope (3.5), and detect negative evolution in the stretch parameter (4.0) and positive evolution in the offset parameter (5.8). This observed evolution, combined with the absence of BCG growth, when stellar mass is measured within 50 kpc, suggests that this evolution results from changes in the cluster's m gap. For this to occur, late-term growth must be in the intracluster light surrounding the BCG. We also compare the observed results to IllustrisTNG 300-1 cosmological hydrodynamic simulations and find modest qualitative agreement. However, the simulations lack the evolutionary features detected in the real data.
  155. Li, T., Ji, A., Pace, A., et al., (including Kuehn, K.), 2022, ApJ, 928, 30, S 5: The Orbital and Chemical Properties of One Dozen Stellar Streams
    We report the kinematic, orbital, and chemical properties of 12 stellar streams with no evident progenitors using line-of-sight velocities and metallicities from the Southern Stellar Stream Spectroscopic Survey (S 5), proper motions from Gaia EDR3, and distances derived from distance tracers or the literature. This data set provides the largest homogeneously analyzed set of streams with full 6D kinematics and metallicities. All streams have heliocentric distances between ~10 and 50 kpc. The velocity and metallicity dispersions show that half of the stream progenitors were disrupted dwarf galaxies (DGs), while the other half originated from disrupted globular clusters (GCs), hereafter referred to as DG and GC streams. Based on the mean metallicities of the streams and the mass-metallicity relation, the luminosities of the progenitors of the DG streams range between those of Carina and Ursa Major I (-9.5 M V -5.5). Four of the six GC streams have mean metallicities of [Fe/H] < -2, more metal poor than typical Milky Way (MW) GCs at similar distances. Interestingly, the 300S and Jet GC streams are the only streams on retrograde orbits in our dozen-stream sample. Finally, we compare the orbital properties of the streams with known DGs and GCs in the MW, finding several possible associations. Some streams appear to have been accreted with the recently discovered Gaia-Enceladus-Sausage system, and others suggest that GCs were formed in and accreted together with the progenitors of DG streams whose stellar masses are similar to those of Draco to Carina (~105-106 M ).
  156. Morgan, R., Nord, B., Bechtol, K., et al., (including Kuehn, K.), 2022, ApJ, 927, 109, DeepZipper: A Novel Deep-learning Architecture for Lensed Supernovae Identification
    Large-scale astronomical surveys have the potential to capture data on large numbers of strongly gravitationally lensed supernovae (LSNe). To facilitate timely analysis and spectroscopic follow-up before the supernova fades, an LSN needs to be identified soon after it begins. To quickly identify LSNe in optical survey data sets, we designed ZipperNet, a multibranch deep neural network that combines convolutional layers (traditionally used for images) with long short-term memory layers (traditionally used for time series). We tested ZipperNet on the task of classifying objects from four categories-no lens, galaxy-galaxy lens, lensed Type-Ia supernova, lensed core-collapse supernova-within high-fidelity simulations of three cosmic survey data sets: the Dark Energy Survey, Rubin Observatory's Legacy Survey of Space and Time (LSST), and a Dark Energy Spectroscopic Instrument (DESI) imaging survey. Among our results, we find that for the LSST-like data set, ZipperNet classifies LSNe with a receiver operating characteristic area under the curve of 0.97, predicts the spectroscopic type of the lensed supernovae with 79% accuracy, and demonstrates similarly high performance for LSNe 1-2 epochs after first detection. We anticipate that a model like ZipperNet, which simultaneously incorporates spatial and temporal information, can play a significant role in the rapid identification of lensed transient systems in cosmic survey experiments.
  157. Lauer, T., Postman, M., Spencer, J., et al., (including Grundy, W.), 2022, ApJL, 927, L8, Anomalous Flux in the Cosmic Optical Background Detected with New Horizons Observations
    We used New Horizons LORRI images to measure the optical-band (0.4 0.9m) sky brightness within a high-galactic-latitude field selected to have reduced diffuse scattered light from the Milky Way galaxy (DGL), as inferred from the IRIS all-sky 100 m map. We also selected the field to significantly reduce the scattered light from bright stars (SSL) outside the LORRI field. Suppression of DGL and SSL reduced the large uncertainties in the background flux levels present in our earlier New Horizons cosmic optical background (COB) results. The raw total sky level, measured when New Horizons was 51.3 au from the Sun, is 24.22 0.80 nW m-2 sr-1. Isolating the COB contribution to the raw total required subtracting scattered light from bright stars and galaxies, faint stars below the photometric detection limit within the field, and the hydrogen plus ionized-helium two-photon continua. This yielded a highly significant detection of the COB at 16.37 1.47 nW m-2 sr-1 at the LORRI pivot wavelength of 0.608 m. This result is in strong tension with the hypothesis that the COB only comprises the integrated light of external galaxies (IGL) presently known from deep HST counts. Subtraction of the estimated IGL flux from the total COB level leaves a flux component of unknown origin at 8.06 1.92 nW m-2 sr-1. Its amplitude is equal to the IGL.
  158. O'Donnell, J., Wilkinson, R., Diehl, H., et al., (including Kuehn, K.), 2022, ApJS, 259, 27, The Dark Energy Survey Bright Arcs Survey: Candidate Strongly Lensed Galaxy Systems from the Dark Energy Survey 5000 Square Degree Footprint
    We report the combined results of eight searches for strong gravitational lens systems in the full 5000 square degrees of Dark Energy Survey (DES) observations. The observations accumulated by the end of the third observing season fully covered the DES footprint in five filters (grizY), with an i-band limiting magnitude (at 10) of 23.44. In four searches, a list of potential candidates was identified using a color and magnitude selection from the object catalogs created from the first three observing seasons. Three other searches were conducted at the locations of previously identified galaxy clusters. Cutout images of potential candidates were then visually scanned using an object viewer. An additional set of candidates came from a data-quality check of a subset of the color-coadd tiles created from the full DES six-season data set. A short list of the most promising strong-lens candidates was then numerically ranked according to whether or not we judged them to be bona fide strong gravitational lens systems. These searches discovered a diverse set of 247 strong-lens candidate systems, of which 81 are identified for the first time. We provide the coordinates, magnitudes, and photometric properties of the lens and source objects, and an estimate of the Einstein radius for 81 new systems and 166 previously reported systems. This catalog will be of use for selecting interesting systems for detailed follow up, studies of galaxy cluster and group mass profiles, as well as a training/validation set for automated strong-lens searches.
  159. Archer, H., Hunter, D., Elmegreen, B., et al., 2022, AJ, 163, 141, The Environments of CO Cores and Star Formation in the Dwarf Irregular Galaxy WLM
    The low metallicities of dwarf irregular galaxies (dIrr) greatly influence the formation and structure of molecular clouds. These clouds, which consist primarily of H2, are typically traced by CO, but low-metallicity galaxies are found to have little CO despite ongoing star formation. In order to probe the conditions necessary for CO core formation in dwarf galaxies, we have used the catalog of Rubio et al. for CO cores in WLM, a Local Group dwarf with an oxygen abundance that is 13% of solar. Here we aim to characterize the galactic environments in which these 57 CO cores formed. We grouped the cores together based on proximity to each other and strong FUV emission, examining properties of the star-forming region enveloping the cores and the surrounding environment where the cores formed. We find that high H I surface density does not necessarily correspond to higher total CO mass, but regions with higher CO mass have higher H I surface densities. We also find the cores in star-forming regions spanning a wide range of ages show no correlation between age and CO core mass, suggesting that the small size of the cores is not due to fragmentation of the clouds with age. The presence of CO cores in a variety of different local environments, along with the similar properties between star-forming regions with and without CO cores, leads us to conclude that there are no obvious environmental characteristics that drive the formation of these CO cores.
  160. Hofgartner, J., Birch, S., Castillo, J., et al., (including Grundy, W.), 2022, Icar, 375, 114835, Hypotheses for Triton's plumes: New analyses and future remote sensing tests
    At least two active plumes were observed on Neptune's moon Triton during the Voyager 2 flyby in 1989. Models for Triton's plumes have previously been grouped into five hypotheses, two of which are primarily atmospheric phenomena and are generally considered unlikely, and three of which include eruptive processes and are plausible. These hypotheses are compared, including new arguments, such as comparisons based on current understanding of Mars, Enceladus, and Pluto. An eruption model based on a solar-powered, solid-state greenhouse effect was previously considered the leading hypothesis for Triton's plumes, in part due to the proximity of the plumes to the subsolar latitude during the Voyager 2 flyby and the distribution of Triton's fans that are putatively deposits from former plumes. The other two eruption hypotheses are powered by internal heat, not solar insolation. Based on new analyses of the ostensible relation between the latitude of the subsolar point on Triton and the geographic locations of the plumes and fans, we argue that neither the locations of the plumes nor fans are strong evidence in favor of the solar-powered hypothesis. We conclude that all three eruption hypotheses should be considered further. Five tests are presented that could be implemented with remote sensing observations from future spacecraft to confidently distinguish among the eruption hypotheses for Triton's plumes. The five tests are based on the: (1) composition and thickness of Triton's southern hemisphere terrains, (2) composition of fan deposits, (3) distribution of active plumes, (4) distribution of fans, and (5) surface temperature at the locations of plumes and/or fans. The tests are independent, but complementary, and implementable with a single flyby mission such as the Trident mission concept. We note that, in the case of the solar-driven hypothesis, the 2030s and 2040s may be the last chance for approximately a century to observe actively erupting plumes on Triton.
  161. Fatka, P., Moskovitz, N., Pravec, P., et al., (including Kueny, J., Skiff, B.), 2022, MNRAS, 510, 6033, Recent formation and likely cometary activity of near-Earth asteroid pair 2019 PR2-2019 QR6
    Asteroid pairs are genetically related asteroids that recently separated (<few million years), but still reside on similar heliocentric orbits. A few hundred of these systems have been identified, primarily in the asteroid main belt. Here, we studied a newly discovered pair of near-Earth objects (NEOs): 2019 PR2 and 2019 QR6. Based on broad-band photometry, we found these asteroids to be spectrally similar to D-types, a type rare amongst NEOs. We recovered astrometric observations for both asteroids from the Catalina Sky Survey from 2005, which significantly improved their fitted orbits. With these refinements we ran backwards orbital integrations to study formation and evolutionary history. We found that neither a pure gravitational model nor a model with the Yarkovsky effect could explain their current orbits. We thus implemented two models of comet-like non-gravitational forces based on water or CO sublimation. The first model assumed quasi-continuous, comet-like activity after separation, which suggested a formation time of the asteroid pair $300^{+120}_{-70}$ yr ago. The second model assumed short-term activity for up to one heliocentric orbit (~13.9 yr) after separation, which suggested that the pair formed 272 7 yr ago. Image stacks showed no activity for 2019 PR2 during its last perihelion passage. These results strongly argue for a common origin that makes these objects the youngest asteroid pair known to date. Questions remain regarding whether these objects derived from a parent comet or asteroid, and how activity may have evolved since their separation.
  162. Leauthaud, A., Amon, A., Singh, S., et al., (including Kuehn, K.), 2022, MNRAS, 510, 6150, Lensing without borders - I. A blind comparison of the amplitude of galaxy-galaxy lensing between independent imaging surveys
    Lensing without borders is a cross-survey collaboration created to assess the consistency of galaxy-galaxy lensing signals () across different data sets and to carry out end-to-end tests of systematic errors. We perform a blind comparison of the amplitude of using lens samples from BOSS and six independent lensing surveys. We find good agreement between empirically estimated and reported systematic errors which agree to better than 2.3 in four lens bins and three radial ranges. For lenses with zL > 0.43 and considering statistical errors, we detect a 3-4 correlation between lensing amplitude and survey depth. This correlation could arise from the increasing impact at higher redshift of unrecognized galaxy blends on shear calibration and imperfections in photometric redshift calibration. At zL > 0.54, amplitudes may additionally correlate with foreground stellar density. The amplitude of these trends is within survey-defined systematic error budgets that are designed to include known shear and redshift calibration uncertainty. Using a fully empirical and conservative method, we do not find evidence for large unknown systematics. Systematic errors greater than 15 per cent (25 per cent) ruled out in three lens bins at 68 per cent (95 per cent) confidence at z < 0.54. Differences with respect to predictions based on clustering are observed to be at the 20-30 per cent level. Our results therefore suggest that lensing systematics alone are unlikely to fully explain the 'lensing is low' effect at z < 0.54. This analysis demonstrates the power of cross-survey comparisons and provides a promising path for identifying and reducing systematics in future lensing analyses.
  163. Metzger, P., Grundy, W., Sykes, M., et al., 2022, Icar, 374, 114768, Moons are planets: Scientific usefulness versus cultural teleology in the taxonomy of planetary science
    We argue that taxonomical concept development is vital for planetary science as in all branches of science, but its importance has been obscured by unique historical developments. The literature shows that the concept of planet developed by scientists during the Copernican Revolution was theory-laden and pragmatic for science. It included both primaries and satellites as planets due to their common intrinsic, geological characteristics. About two centuries later the non-scientific public had just adopted heliocentrism and was motivated to preserve elements of geocentrism including teleology and the assumptions of astrology. This motivated development of a folk concept of planet that contradicted the scientific view. The folk taxonomy was based on what an object orbits, making satellites out to be non-planets and ignoring most asteroids. Astronomers continued to keep primaries and moons classed together as planets and continued teaching that taxonomy until the 1920s. The astronomical community lost interest in planets ca. 1910 to 1955 and during that period complacently accepted the folk concept. Enough time has now elapsed so that modern astronomers forgot this history and rewrote it to claim that the folk taxonomy is the one that was created by the Copernican scientists. Starting ca. 1960 when spacecraft missions were developed to send back detailed new data, there was an explosion of publishing about planets including the satellites, leading to revival of the Copernican planet concept. We present evidence that taxonomical alignment with geological complexity is the most useful scientific taxonomy for planets. It is this complexity of both primary and secondary planets that is a key part of the chain of origins for life in the cosmos.
  164. Reddy, V., Kelley, M., Dotson, J., et al., (including Moskovitz, N., Devogele, M., Skiff, B.), 2022, Icar, 374, 114790, Near-earth asteroid (66391) Moshup (1999 KW4) observing campaign: Results from a global planetary defense characterization exercise
    Hazards due to near-Earth objects (NEOs) continue to pose a threat to life on Earth. While our capability for discovering NEOs has steadily progressed over the last three decades, physical characterization of a representative population has lagged behind. To test the operational readiness of the global planetary defense capabilities, we conducted a community-led global planetary defense exercise, with support from the NASA's Planetary Defense Coordination Office (PDCO) and the International Asteroid Warning Network (IAWN), to test the operational readiness of global planetary defense capabilities. This campaign focused on the characterization (direct imaging, radar, spectroscopy) of the binary near-Earth asteroid (NEA) (66391) Moshup (formerly known as 1999 KW4) and its moon Squannit. We chose a binary system because roughly one in six large NEAs are binaries. An additional goal was to apply lessons learned from this campaign towards ground-based characterization campaign for binary NEA (65803) Didymos, the target of the PDCO's Double Asteroid Redirection Test (DART) and the European Space Agency's Hera missions. Spectral observations of Moshup from the NASA Infrared Telescope Facility (IRTF) show similarities to Q-type asteroids. Based on its spectral band parameters, the best meteorite analogs for Moshup are L chondrites. We did not detect a hydration feature at 3 m, which suggests that the entire surface is anhydrous. We imaged the binary using the SPHERE instrument on the Very Large Telescope (VLT) and obtained resolved spectral measurements of Moshup similar to those obtained with the NASA IRTF. Squannit appears to have slightly redder spectral slope than Moshup. Radar observations Arecibo Observatory at 2380 MHz indicate a polarization ratio of ~0.4, which is higher than the average values for the S complex asteroids, which includes Q types. The visible extent of the components from the radar observations, taken as proxies for their radii, suggest Moshup and Squannit have diameters of 1500 120 m and 480 60 m, respectively. We constrain the system mass to 2.2 0.5 1012 kg with a maximum range for bulk density between ~0.8 g/cm3 for a very low-mass system with spherical shapes up to 2.7 g/cm3 for very high-mass system where Moshup has a more ridged-ball shape. We note that the radar-derived parameters presented in the paper are for the purposes of this exercise and do not supersede those in Ostro et al. (2006). We assessed the impact risk of a hypothetical impactor based on Moshup's physical properties using the Probabilistic Asteroid Impact Risk (PAIR) model. We assessed three impact risk scenarios at different epochs as the state of knowledge of Moshup improved. For kilometer-scale impactors like Moshup, the risk is driven predominantly by the potential for global climatic effects (95-97% of cases across the epochs) with a few percent driven by local damage and a few tenths of a percent driven by tsunami.
  165. Guise, E., Honig, S., Almeyda, T., et al., (including Kuehn, K.), 2022, MNRAS, 510, 3145, Multiwavelength optical and NIR variability analysis of the Blazar PKS 0027-426
    We present multiwavelength spectral and temporal variability analysis of PKS 0027-426 using optical griz observations from Dark Energy Survey between 2013 and 2018 and VEILS Optical Light curves of Extragalactic TransienT Events (VOILETTE) between 2018 and 2019 and near-infrared (NIR) JKs observations from Visible and Infrared Survey Telescope for Astronomy Extragalactic Infrared Legacy Survey (VEILS) between 2017 and 2019. Multiple methods of cross-correlation of each combination of light curve provides measurements of possible lags between optical-optical, optical-NIR, and NIR-NIR emission, for each observation season and for the entire observational period. Inter-band time lag measurements consistently suggest either simultaneous emission or delays between emission regions on time-scales smaller than the cadences of observations. The colour-magnitude relation between each combination of filters was also studied to determine the spectral behaviour of PKS 0027-426. Our results demonstrate complex colour behaviour that changes between bluer when brighter, stable when brighter, and redder when brighter trends over different time-scales and using different combinations of optical filters. Additional analysis of the optical spectra is performed to provide further understanding of this complex spectral behaviour.
  166. Schindler, K., 2022, BAAS, 54, 018, Obituary: Carolyn J. Shoemaker (1923-2020)
    Shoemaker was a prolific discoverer of minor planets and comets. She was co-discoverer of Comet Shoemaker-Levy 9, whose impact on Jupiter garnered world-wide attention to the risk of impacts on Earth.
  167. Holler, B., Yanez, M., Protopapa, S., et al., (including Grundy, W.), 2022, Icar, 373, 114729, Evaluation of short-term temporal evolution of Pluto's surface composition from 2014-2017 with APO/TripleSpec
    In this work we present the results of a spectral observing campaign of Pluto to search for temporal changes in surface composition on 1- to 3-year timescales. Near-infrared spectra of Pluto were obtained from June 2014 to August 2017 with the TripleSpec cross-dispersed spectrograph at the Apache Point Observatory's 3.5-meter Astrophysical Research Consortium (ARC) telescope. Observations were requested in order to obtain spectra of approximately the same sub-observer hemisphere 14 months apart, thus removing the effects of viewing geometry and rotation phase. Comparison of the CH4 (methane) band areas and band center shifts between each component of these "matched pairs" revealed a surface in transition. Band areas for the 1.66 and 1 . 72 m CH4 absorption features exhibited a >5- increase between 2014-06-17 and 2015-08-19, corresponding to a sub-observer hemisphere centered at 280E, with the latter date only 1 month after the New Horizons flyby of Pluto. The majority of matched pairs were obtained of the anti-Charon hemisphere, home to the bright, volatile-rich Sputnik Planitia, and did not present statistically significant changes in CH4 band areas. CH4 band center shifts, which provide information on the mixing state of CH4 and N2 in solid solution, were calculated between components of each matched pair, with no significant band shifts detected. The favored explanation for these combined results is the sublimation of more-volatile N2 from the northern latitudes of Pluto in the lead-up to northern hemisphere summer solstice in 2029, leading to an increase in CH4 concentration.
  168. Bertrand, T., Lellouch, E., Holler, B., et al., (including Grundy, W.), 2022, Icar, 373, 114764, Volatile transport modeling on Triton with new observational constraints
    Neptune's moon Triton shares many similarities with Pluto, including volatile cycles of N2, CH4 and CO, and represents a benchmark case for the study of surface-atmosphere interactions on volatile-rich Kuiper Belt objects. The observations of Pluto by New Horizons acquired during the 2015 flyby and their analysis with volatile transport models (VTMs) shed light on how volatile sublimation-condensation cycles control the climate and shape the surface of such objects. Within the context of New Horizons observations as well as recent Earth-based observations of Triton, we adapt a Plutonian VTM to Triton, and test its ability to simulate its volatile cycles, thereby aiding our understanding of its climate.

    Here we present numerical VTM simulations exploring the volatile cycles of N2, CH4 and CO on Triton over long-term and seasonal timescales (cap extent, surface temperatures, surface pressure, sublimation rates) for varying model parameters (including the surface ice reservoir, albedo, thermal inertia, and the internal heat flux). We explore what scenarios and model parameters allow for a best match of the available observations. In particular, our set of observational constraints include Voyager 2 observations (surface pressure and cap extent), ground-based near-infrared (0.8-2.4 m) disk-integrated spectra (the relative surface area of volatile vs. non-volatile ice) and the evolution of surface pressure as retrieved from stellar occultations.

    Our results show that Triton's poles act as cold traps for volatile ices and favor the formation of polar caps extending to lower latitudes through glacial flow or through the formation of thinner seasonal deposits. As previously evidenced by other VTMs, North-South asymmetries in surface properties can favor the development of one cap over the other. Our best-case simulations are obtained for a bedrock surface albedo of 0.6-0.7, a global reservoir of N2 ice thicker than 200 m, and a bedrock thermal inertia larger than 500 SI (or smaller but with a large internal heat flux). The large N2 ice reservoir implies a permanent N2 southern cap (several 100 m thick) extending to the equatorial regions with higher amounts of volatile ice at the south pole, which is not inconsistent with Voyager 2 images but does not fit well with observed full-disk near-infrared spectra. Our results also suggest that a small permanent polar cap exists in the northern (currently winter) hemisphere if the internal heat flux remains relatively low (e.g. radiogenic, < 3 mW m-2). A non-permanent northern polar cap was only obtained in some of our simulations with high internal heat flux (30 mW m-2). The northern cap will possibly extend to 30N in the next decade, thus becoming visible by Earth-based telescopes. On the basis of our model results, we also discuss the composition of several surface units seen by Voyager 2 in 1989, including the bright equatorial fringe and dark surface patches.

    Finally, we provide predictions for the evolution of ice distribution, surface pressure and CO and CH4 atmospheric mixing ratios in the next decades. According to our model, the surface pressure should slowly decrease but remain larger than 0.5 Pa by 2060. We also model the thermal lightcurves of Triton for different climate scenarios in 2022, which serve as predictions for future James Webb Space Telescope observations.

  169. Earle, A., Binzel, R., Keane, J., et al., (including Grundy, W.), 2022, Icar, 373, 114771, Tracing seasonal trends across Pluto's craters: New Horizons Ralph/MVIC results
    The July 2015 encounter of the Pluto system by the NASA New Horizons spacecraft has facilitated the study of Pluto's origin, surface processes, volatile transport cycles, and the energetics and chemistry of its atmosphere in an unprecedented level of detail. Earle et al. (2018b) presented the highest spatial resolution composition maps of Pluto using data from the Ralph/MVIC instrument and provided a global interpretation of the maps. Here we build upon that work and leverage MVIC's high spatial resolution to study the volatile distribution in and around craters to better understand how small scale topography affects volatile transport. We find that the compositional morphology in and around craters in our study can be divided into four different latitudinal bands, where differences are found for distribution trends in nitrogen, methane, and organic signatures in crater floors, walls, and surrounding slopes. We summarize the compositional characteristics of a "typical" crater in each latitude band, provide some possible explanation for the distribution based on current volatile transport models, and highlight some questions to be addressed by ongoing models.
  170. Dimitrova, T., Neugent, K., Massey, P., et al., 2022, AJ, 163, 70, Locating Red Supergiants in the Galaxy NGC 6822
    Using archival near-IR photometry, we identify 51 of the K-band brightest red supergiants (RSGs) in NGC 6822 and compare their physical properties with stellar evolutionary model predictions. We first use Gaia parallax and proper motion values to filter out foreground Galactic red dwarfs before constructing a J-K versus K color-magnitude diagram to eliminate lower-mass asymptotic giant branch star contaminants in NGC 6822. We then cross match our results to previously spectroscopically confirmed RSGs and other NGC 6822 content studies and discuss our overall completeness, concluding that radial velocity alone is an insufficient method of determining membership in NGC 6822. After transforming the J and K magnitudes to effective temperatures and luminosities, we compare these physical properties with predictions from both the Geneva single-star and Binary Population and Spectral Synthesis (BPASS) single and binary-star evolution tracks. We find that our derived temperatures and luminosities match the evolutionary model predictions well, however, the BPASS model, which includes the effects of binary evolution, provides the best overall fit. This revealed the presence of a group of cool RSGs in NGC 6822, suggesting a history of binary interaction. We hope this work will lead to further comparative RSG studies in other Local Group galaxies, opportunities for direct spectroscopic follow-up, and a better understanding of evolutionary model predictions.
  171. Wang, X., Rice, M., Wang, S., et al., (including Skiff, B., Polakis, T., Llama, J.), 2022, ApJL, 926, L8, The Aligned Orbit of WASP-148b, the Only Known Hot Jupiter with a nearby Warm Jupiter Companion, from NEID and HIRES
    We present spectroscopic measurements of the Rossiter-McLaughlin effect for WASP-148b, the only known hot Jupiter with a nearby warm-Jupiter companion, from the WIYN/NEID and Keck/HIRES instruments. This is one of the first scientific results reported from the newly commissioned NEID spectrograph, as well as the second obliquity constraint for a hot Jupiter system with a close-in companion, after WASP-47. WASP-148b is consistent with being in alignment with the sky-projected spin axis of the host star, with $\lambda =-8\buildrel{\circ}\over{.} {2}_{-9\buildrel{\circ}\over{.} \,7}^{+8\buildrel{\circ}\over{.} \,7}$ . The low obliquity observed in the WASP-148 system is consistent with the orderly-alignment configuration of most compact multi-planet systems around cool stars with obliquity constraints, including our solar system, and may point to an early history for these well-organized systems in which migration and accretion occurred in isolation, with relatively little disturbance. By contrast, previous results have indicated that high-mass and hot stars appear to more commonly host a wide range of misaligned planets: not only single hot Jupiters, but also compact systems with multiple super-Earths. We suggest that, to account for the high rate of spin-orbit misalignments in both compact multi-planet and isolated-hot-Jupiter systems orbiting high-mass and hot stars, spin-orbit misalignments may be caused by distant giant planet perturbers, which are most common around these stellar types.
  172. Abbott, T., Aguena, M., Allam, S., et al., (including Kuehn, K., DES Collaboration), 2022, PhRvD, 105, 043512, Dark Energy Survey Year 3 results: A 2.7% measurement of baryon acoustic oscillation distance scale at redshift 0.835
    We present angular diameter measurements obtained by measuring the position of baryon acoustic oscillations (BAO) in an optimized sample of galaxies from the first three years of Dark Energy Survey data (DES Y3). The sample consists of 7 million galaxies distributed over a footprint of 4100 deg2 with 0.6 <zphoto<1.1 and a typical redshift uncertainty of 0.03 (1 +z ). The sample selection is the same as in the BAO measurement with the first year of DES data, but the analysis presented here uses three times the area, extends to higher redshift, and makes a number of improvements, including a fully analytical BAO template, the use of covariances from both theory and simulations, and an extensive preunblinding protocol. We used two different statistics; angular correlation function and power spectrum, and validate our pipeline with an ensemble of over 1500 realistic simulations. Both statistics yield compatible results. We combine the likelihoods derived from angular correlations and spherical harmonics to constrain the ratio of comoving angular diameter distance DM at the effective redshift of our sample to the sound horizon scale at the drag epoch. We obtain DM(zeff=0.835 )/rd=18.92 0.51 , which is consistent with, but smaller than, the Planck prediction assuming flat CDM , at the level of 2.3 . The analysis was performed blind and is robust to changes in a number of analysis choices. It represents the most precise BAO distance measurement from imaging data to date, and is competitive with the latest transverse ones from spectroscopic samples at z >0.75 . When combined with DES 3 x 2 pt +SNIa , they lead to improvements in H0 and m constraints by 20 %.
  173. Bernardinelli, P., Bernstein, G., Sako, M., et al., (including Kuehn, K.), 2022, ApJS, 258, 41, A Search of the Full Six Years of the Dark Energy Survey for Outer Solar System Objects
    We present a search for outer solar system objects in the 6 yr of data from the Dark Energy Survey (DES). The DES covered a contiguous 5000 deg2 of the southern sky with 80,000 3 deg2 exposures in the grizY filters between 2013 and 2019. This search yielded 812 trans-Neptunian objects (TNOs), one Centaur and one Oort cloud comet, 458 reported here for the first time. We present methodology that builds upon our previous search on the first 4 yr of data. All images were reprocessed with an optimized detection pipeline that leads to an average completeness gain of 0.47 mag per exposure, as well as improved transient catalog production and algorithms for linkage of detections into orbits. All objects were verified by visual inspection and by the "sub-threshold significance," the signal-to-noise ratio in the stack of images in which its presence is indicated by the orbit, but no detection was reported. This yields a pure catalog complete to r 23.8 mag and distances 29 < d < 2500 au. The TNOs have minimum (median) of 7 (12) nights' detections and arcs of 1.1 (4.2) yr, and will have grizY magnitudes available in a further publication. We present software for simulating our observational biases for comparisons of models to our detections. Initial inferences demonstrating the catalog's statistical power are: the data are inconsistent with the CFEPS-L7 model for the classical Kuiper Belt; the 16 "extreme" TNOs (a > 150 au, q > 30 au) are consistent with the null hypothesis of azimuthal isotropy; and nonresonant TNOs with q > 38 au, a > 50 au show a significant tendency to be sunward of major mean-motion resonances.
  174. Tavangar, K., Ferguson, P., Shipp, N., et al., (including Kuehn, K.), 2022, ApJ, 925, 118, From the Fire: A Deeper Look at the Phoenix Stream
    We use 6 yr of data from the Dark Energy Survey to perform a detailed photometric characterization of the Phoenix stellar stream, a 15 long, thin, dynamically cold, low-metallicity stellar system in the Southern Hemisphere. We use natural splines, a nonparametric modeling technique, to simultaneously fit the stream track, width, and linear density. This updated stream model allows us to improve measurements of the heliocentric distance (17.4 0.1 (stat.) 0.8 (sys.) kpc) and distance gradient (-0.009 0.006 kpc deg-1) of Phoenix, which corresponds to a small change of 0.13 0.09 kpc in heliocentric distance along the length of the stream. We measure linear intensity variations on degree scales, as well as deviations in the stream track on ~2 scales, suggesting that the stream may have been disturbed during its formation and/or evolution. We recover three peaks and one gap in linear intensity along with fluctuations in the stream track. Compared to other thin streams, the Phoenix stream shows more fluctuations and, consequently, the study of Phoenix offers a unique perspective on gravitational perturbations of stellar streams. We discuss possible sources of perturbations to Phoenix, including baryonic structures in the Galaxy and dark matter subhalos.
  175. Boro Saikia, S., Luftinger, T., Folsom, C., et al., (including Hall, J.), 2022, A&A, 658, A16, Time evolution of magnetic activity cycles in young suns: The curious case of Ceti
    Context. A detailed investigation of the magnetic properties of young Sun-like stars can provide valuable information on our Sun's magnetic past and its impact on the early Earth.
    Aims: We determine the properties of the moderately rotating young Sun-like star Ceti's magnetic and activity cycles using 50 yr of chromospheric activity data and six epochs of spectropolarimetric observations.
    Methods: The chromospheric activity was determined by measuring the flux in the Ca II H and K lines. A generalised Lomb-Scargle periodogram and a wavelet decomposition were used on the chromospheric activity data to establish the associated periodicities. The vector magnetic field of the star was reconstructed using the technique of Zeeman Doppler imaging on the spectropolarimetric observations.
    Results: Our period analysis algorithms detect a 3.1 yr chromospheric cycle in addition to the star's well-known ~6 yr cycle period. Although the two cycle periods have an approximate 1:2 ratio, they exhibit an unusual temporal evolution. Additionally, the spectropolarimetric data analysis shows polarity reversals of the star's large-scale magnetic field, suggesting a ~10 yr magnetic or Hale cycle.
    Conclusions: The unusual evolution of the star's chromospheric cycles and their lack of a direct correlation with the magnetic cycle establishes Ceti as a curious young Sun. Such complex evolution of magnetic activity could be synonymous with moderately active young Suns, which is an evolutionary path that our own Sun could have taken.
  176. Kovacs, A., Jeffrey, N., Gatti, M., et al., (including Kuehn, K.), 2022, MNRAS, 510, 216, The DES view of the Eridanus supervoid and the CMB cold spot
    The Cold Spot is a puzzling large-scale feature in the Cosmic Microwave Background temperature maps and its origin has been subject to active debate. As an important foreground structure at low redshift, the Eridanus supervoid was recently detected, but it was subsequently determined that, assuming the standard CDM model, only about 10-20 per cent of the observed temperature depression can be accounted for via its Integrated Sachs-Wolfe imprint. However, R 100 h-1Mpc supervoids elsewhere in the sky have shown ISW imprints AISW 5.2 1.6 times stronger than expected from CDM (AISW = 1), which warrants further inspection. Using the Year-3 redMaGiC catalogue of luminous red galaxies from the Dark Energy Survey, here we confirm the detection of the Eridanus supervoid as a significant underdensity in the Cold Spot's direction at z < 0.2. We also show, with S/N 5 significance, that the Eridanus supervoid appears as the most prominent large-scale underdensity in the dark matter mass maps that we reconstructed from DES Year-3 gravitational lensing data. While we report no significant anomalies, an interesting aspect is that the amplitude of the lensing signal from the Eridanus supervoid at the Cold Spot centre is about 30 per cent lower than expected from similar peaks found in N-body simulations based on the standard CDM model with parameters m = 0.279 and 8 = 0.82. Overall, our results confirm the causal relation between these individually rare structures in the cosmic web and in the CMB, motivating more detailed future surveys in the Cold Spot region.
  177. Gatti, M., Giannini, G., Bernstein, G., et al., (including Kuehn, K.), 2022, MNRAS, 510, 1223, Dark Energy Survey Year 3 Results: clustering redshifts - calibration of the weak lensing source redshift distributions with redMaGiC and BOSS/eBOSS
    We present the calibration of the Dark Energy Survey Year 3 (DES Y3) weak lensing (WL) source galaxy redshift distributions n(z) from clustering measurements. In particular, we cross-correlate the WL source galaxies sample with redMaGiC galaxies (luminous red galaxies with secure photometric redshifts) and a spectroscopic sample from BOSS/eBOSS to estimate the redshift distribution of the DES sources sample. Two distinct methods for using the clustering statistics are described. The first uses the clustering information independently to estimate the mean redshift of the source galaxies within a redshift window, as done in the DES Y1 analysis. The second method establishes a likelihood of the clustering data as a function of n(z), which can be incorporated into schemes for generating samples of n(z) subject to combined clustering and photometric constraints. Both methods incorporate marginalization over various astrophysical systematics, including magnification and redshift-dependent galaxy-matter bias. We characterize the uncertainties of the methods in simulations; the first method recovers the mean z of tomographic bins to RMS (precision) of ~0.014. Use of the second method is shown to vastly improve the accuracy of the shape of n(z) derived from photometric data. The two methods are then applied to the DES Y3 data.
  178. Varga, T., Gruen, D., Seitz, S., et al., (including Kuehn, K.), 2022, MNRAS, 509, 4865, Synthetic galaxy clusters and observations based on Dark Energy Survey Year 3 Data
    We develop a novel data-driven method for generating synthetic optical observations of galaxy clusters. In cluster weak lensing, the interplay between analysis choices and systematic effects related to source galaxy selection, shape measurement, and photometric redshift estimation can be best characterized in end-to-end tests going from mock observations to recovered cluster masses. To create such test scenarios, we measure and model the photometric properties of galaxy clusters and their sky environments from the Dark Energy Survey Year 3 (DES Y3) data in two bins of cluster richness $\lambda \in [30; 45)$, $\lambda \in [45; 60)$ and three bins in cluster redshift ($z\in [0.3; 0.35)$, $z\in [0.45; 0.5)$ and $z\in [0.6; 0.65)$. Using deep-field imaging data, we extrapolate galaxy populations beyond the limiting magnitude of DES Y3 and calculate the properties of cluster member galaxies via statistical background subtraction. We construct mock galaxy clusters as random draws from a distribution function, and render mock clusters and line-of-sight catalogues into synthetic images in the same format as actual survey observations. Synthetic galaxy clusters are generated from real observational data, and thus are independent from the assumptions inherent to cosmological simulations. The recipe can be straightforwardly modified to incorporate extra information, and correct for survey incompleteness. New realizations of synthetic clusters can be created at minimal cost, which will allow future analyses to generate the large number of images needed to characterize systematic uncertainties in cluster mass measurements.
  179. Lee, S., Huff, E., Choi, A., et al., (including Kuehn, K.), 2022, MNRAS, 509, 4982, Probing gravity with the DES-CMASS sample and BOSS spectroscopy
    The DES-CMASS sample (DMASS) is designed to optimally combine the weak lensing measurements from the Dark Energy Survey (DES) and redshift-space distortions (RSD) probed by the CMASS galaxy sample from the Baryonic Oscillation Spectroscopic Survey. In this paper, we demonstrate the feasibility of adopting DMASS as the equivalent of CMASS for a joint analysis of DES and BOSS in the framework of modified gravity. We utilize the angular clustering of the DMASS galaxies, cosmic shear of the DES METACALIBRATION sources, and cross-correlation of the two as data vectors. By jointly fitting the combination of the data with the RSD measurements from the CMASS sample and Planck data, we obtain the constraints on modified gravity parameters $\mu _0=-0.37^{+0.47}_{-0.45}$ and $\Sigma _0=0.078^{+0.078}_{-0.082}$. Our constraints of modified gravity with DMASS are tighter than those with the DES Year 1 REDMAGIC sample with the same external data sets by 29 per cent for 0 and 21 per cent for 0, and comparable to the published results of the DES Year 1 modified gravity analysis despite this work using fewer external data sets. This improvement is mainly because the galaxy bias parameter is shared and more tightly constrained by both CMASS and DMASS, effectively breaking the degeneracy between the galaxy bias and other cosmological parameters. Such an approach to optimally combine photometric and spectroscopic surveys using a photometric sample equivalent to a spectroscopic sample can be applied to combining future surveys having a limited overlap such as DESI and LSST.
  180. Ramiaramanantsoa, T., Bowman, J., Shkolnik, E., et al., (including Llama, J.), 2022, MNRAS, 509, 5702, Onboard dynamic image exposure control for the Star-Planet Activity Research CubeSat (SPARCS)
    The Star-Planet Activity Research CubeSat (SPARCS) is a 6U CubeSat under development to monitor the flaring and chromospheric activity of M dwarfs at near-ultraviolet (NUV) and far-ultraviolet (FUV) wavelengths. The spacecraft hosts two UV-optimized delta-doped charge-coupled devices fed by a 9-cm telescope and a dichroic beam splitter. A dedicated science payload processor performs near-real-time onboard science image processing to dynamically change detector integration times and gains to reduce the occurrence of pixel saturation during strong M dwarf flaring events and provide adequate flare light-curve structure resolution while enabling the detection of low-amplitude rotational modulation. The processor independently controls the NUV and FUV detectors. For each detector, it derives control updates from the most recent completed exposure and applies them to the next exposure. The detection of a flare event in the NUV channel resets the exposure in the FUV channel with new exposure parameters. Implementation testing of the control algorithm using simulated light curves and full-frame images demonstrates a robust response to the quiescent and flaring levels expected for the stars to be monitored by the mission. The SPARCS onboard autonomous exposure control algorithm is adaptable for operation in future point source-targeting space-based and ground-based observatories geared towards the monitoring of extreme transient astrophysics phenomena.
  181. Cartwright, R., Nordheim, T., DeColibus, R., et al., (including Grundy, W.), 2022, PSJ, 3, 8, A CO2 Cycle on Ariel? Radiolytic Production and Migration to Low-latitude Cold Traps
    CO2 ice is present on the trailing hemisphere of Ariel but is mostly absent from its leading hemisphere. The leading/trailing hemispherical asymmetry in the distribution of CO2 ice is consistent with radiolytic production of CO2, formed by charged particle bombardment of H2O ice and carbonaceous material in Ariel's regolith. This longitudinal distribution of CO2 on Ariel was previously characterized using 13 near-infrared reflectance spectra collected at "low" sub-observer latitudes between 30S and 30N. Here we investigated the distribution of CO2 ice on Ariel using 18 new spectra: 2 collected over low sub-observer latitudes, 5 collected at "mid" sub-observer latitudes (31N-44N), and 11 collected over "high" sub-observer latitudes (45N-51N). Analysis of these data indicates that CO2 ice is primarily concentrated on Ariel's trailing hemisphere. However, CO2 ice band strengths are diminished in the spectra collected over mid and high sub-observer latitudes. This sub-observer latitudinal trend may result from radiolytic production of CO2 molecules at high latitudes and subsequent migration of this constituent to low-latitude cold traps. We detected a subtle feature near 2.13 m in two spectra collected over high sub-observer latitudes, which might result from a "forbidden" transition mode of CO2 ice that is substantially stronger in well-mixed substrates composed of CO2 and H2O ice, consistent with regolith-mixed CO2 ice grains formed by radiolysis. Additionally, we detected a 2.35 m feature in some low sub-observer latitude spectra, which might result from CO formed as part of a CO2 radiolytic production cycle.
  182. Secco, L., Samuroff, S., Krause, E., et al., (including Kuehn, K.), 2022, PhRvD, 105, 023515, Dark Energy Survey Year 3 results: Cosmology from cosmic shear and robustness to modeling uncertainty
    This work and its companion paper, Amon et al. [Phys. Rev. D 105, 023514 (2022), 10.1103/PhysRevD.105.023514], present cosmic shear measurements and cosmological constraints from over 100 million source galaxies in the Dark Energy Survey (DES) Year 3 data. We constrain the lensing amplitude parameter S88{m/0.3 } at the 3% level in CDM : S8=0.75 9-0.023+0.025 (68% CL). Our constraint is at the 2% level when using angular scale cuts that are optimized for the CDM analysis: S8=0.77 2-0.017+0.018 (68% CL). With cosmic shear alone, we find no statistically significant constraint on the dark energy equation-of-state parameter at our present statistical power. We carry out our analysis blind, and compare our measurement with constraints from two other contemporary weak lensing experiments: the Kilo-Degree Survey (KiDS) and Hyper-Suprime Camera Subaru Strategic Program (HSC). We additionally quantify the agreement between our data and external constraints from the Cosmic Microwave Background (CMB). Our DES Y3 result under the assumption of CDM is found to be in statistical agreement with Planck 2018, although favors a lower S8 than the CMB-inferred value by 2.3 (a p -value of 0.02). This paper explores the robustness of these cosmic shear results to modeling of intrinsic alignments, the matter power spectrum and baryonic physics. We additionally explore the statistical preference of our data for intrinsic alignment models of different complexity. The fiducial cosmic shear model is tested using synthetic data, and we report no biases greater than 0.3 in the plane of S8m caused by uncertainties in the theoretical models.
  183. Roettenbacher, R., Cabot, S., Fischer, D., et al., (including Llama, J., Kuehn, K., Levine, S.), 2022, AJ, 163, 19, EXPRES. III. Revealing the Stellar Activity Radial Velocity Signature of Eridani with Photometry and Interferometry
    The distortions of absorption line profiles caused by photospheric brightness variations on the surfaces of cool, main-sequence stars can mimic or overwhelm radial velocity (RV) shifts due to the presence of exoplanets. The latest generation of precision RV spectrographs aims to detect velocity amplitudes 10 cm s-1, but requires mitigation of stellar signals. Statistical techniques are being developed to differentiate between Keplerian and activity-related velocity perturbations. Two important challenges, however, are the interpretability of the stellar activity component as RV models become more sophisticated, and ensuring the lowest-amplitude Keplerian signatures are not inadvertently accounted for in flexible models of stellar activity. For the K2V exoplanet host Eridani, we separately used ground-based photometry to constrain Gaussian processes for modeling RVs and TESS photometry with a light-curve inversion algorithm to reconstruct the stellar surface. From the reconstructions of TESS photometry, we produced an activity model that reduced the rms scatter in RVs obtained with EXPRES from 4.72 to 1.98 m s-1. We present a pilot study using the CHARA Array and MIRC-X beam combiner to directly image the starspots seen in the TESS photometry. With the limited phase coverage, our spot detections are marginal with current data but a future dedicated observing campaign should allow for imaging, as well as allow the stellar inclination and orientation with respect to the debris disk to be definitively determined. This work shows that stellar surface maps obtained with high-cadence, time-series photometric and interferometric data can provide the constraints needed to accurately reduce RV scatter.
  184. Zakri, W., Megeath, S., Fischer, W., et al., (including Allen, T.), 2022, ApJL, 924, L23, The Rate, Amplitude, and Duration of Outbursts from Class 0 Protostars in Orion
    At least half of a protostar's mass is accreted in the Class 0 phase, when the central protostar is deeply embedded in a dense, infalling envelope. We present the first systematic search for outbursts from Class 0 protostars in the Orion clouds. Using photometry from Spitzer/IRAC spanning 2004 to 2017, we detect three outbursts from Class 0 protostars with 2 mag changes at 3.6 or 4.5 m. This is comparable to the magnitude change of a known protostellar FU Ori outburst. Two are newly detected bursts from the protostars HOPS 12 and 124. The number of detections implies that Class 0 protostars burst every 438 yr, with a 95% confidence interval of 161 to 1884 yr. Combining Spitzer and WISE/NEOWISE data spanning 2004-2019, we show that the bursts persist for more than nine years with significant variability during each burst. Finally, we use 19-100 m photometry from SOFIA, Spitzer, and Herschel to measure the amplitudes of the bursts. Based on the burst interval, a duration of 15 yr, and the range of observed amplitudes, 3%-100% of the mass accretion during the Class 0 phase occurs during bursts. In total, we show that bursts from Class 0 protostars are as frequent, or even more frequent, than those from more evolved protostars. This is consistent with bursts being driven by instabilities in disks triggered by rapid mass infall. Furthermore, we find that bursts may be a significant, if not dominant, mode of mass accretion during the Class 0 phase.
  185. Amon, A., Gruen, D., Troxel, M., et al., (including Kuehn, K., DES Collaboration), 2022, PhRvD, 105, 023514, Dark Energy Survey Year 3 results: Cosmology from cosmic shear and robustness to data calibration
    <related-article ext-link-type="doi" related-article-type="companion" xlink:href="10.1103/PhysRevD.105.023515"/>This work, together with its companion paper, Secco, Samuroff et al. [Phys. Rev. D 105, 023515 (2022), 10.1103/PhysRevD.105.023515], present the Dark Energy Survey Year 3 cosmic-shear measurements and cosmological constraints based on an analysis of over 100 million source galaxies. With the data spanning 4143 deg2 on the sky, divided into four redshift bins, we produce a measurement with a signal-to-noise of 40. We conduct a blind analysis in the context of the Lambda-Cold Dark Matter ( CDM ) model and find a 3% constraint of the clustering amplitude, S88(m/0.3 )0.5=0.75 9-0.023+0.025. A CDM -Optimized analysis, which safely includes smaller scale information, yields a 2% precision measurement of S8=0.77 2-0.017+0.018 that is consistent with the fiducial case. The two low-redshift measurements are statistically consistent with the Planck Cosmic Microwave Background result, however, both recovered S8 values are lower than the high-redshift prediction by 2.3 and 2.1 (p -values of 0.02 and 0.05), respectively. The measurements are shown to be internally consistent across redshift bins, angular scales and correlation functions. The analysis is demonstrated to be robust to calibration systematics, with the S8 posterior consistent when varying the choice of redshift calibration sample, the modeling of redshift uncertainty and methodology. Similarly, we find that the corrections included to account for the blending of galaxies shifts our best-fit S8 by 0.5 without incurring a substantial increase in uncertainty. We examine the limiting factors for the precision of the cosmological constraints and find observational systematics to be subdominant to the modeling of astrophysics. Specifically, we identify the uncertainties in modeling baryonic effects and intrinsic alignments as the limiting systematics.
  186. Abbott, T., Aguena, M., Alarcon, A., et al., (including Kuehn, K., DES Collaboration), 2022, PhRvD, 105, 023520, Dark Energy Survey Year 3 results: Cosmological constraints from galaxy clustering and weak lensing
    We present the first cosmology results from large-scale structure using the full 5000 deg2 of imaging data from the Dark Energy Survey (DES) Data Release 1. We perform an analysis of large-scale structure combining three two-point correlation functions (3 2 pt ): (i) cosmic shear using 100 million source galaxies, (ii) galaxy clustering, and (iii) the cross-correlation of source galaxy shear with lens galaxy positions, galaxy-galaxy lensing. To achieve the cosmological precision enabled by these measurements has required updates to nearly every part of the analysis from DES Year 1, including the use of two independent galaxy clustering samples, modeling advances, and several novel improvements in the calibration of gravitational shear and photometric redshift inference. The analysis was performed under strict conditions to mitigate confirmation or observer bias; we describe specific changes made to the lens galaxy sample following unblinding of the results and tests of the robustness of our results to this decision. We model the data within the flat CDM and w CDM cosmological models, marginalizing over 25 nuisance parameters. We find consistent cosmological results between the three two-point correlation functions; their combination yields clustering amplitude S8=0.77 6-0.017+0.017 and matter density m=0.33 9-0.031+0.032 in CDM , mean with 68% confidence limits; S8=0.77 5-0.024+0.026, m=0.35 2-0.041+0.035, and dark energy equation-of-state parameter w =-0.9 8-0.20+0.32 in w CDM . These constraints correspond to an improvement in signal-to-noise of the DES Year 3 3 2 pt data relative to DES Year 1 by a factor of 2.1, about 20% more than expected from the increase in observing area alone. This combination of DES data is consistent with the prediction of the model favored by the Planck 2018 cosmic microwave background (CMB) primary anisotropy data, which is quantified with a probability-to-exceed p =0.13 -0.48. We find better agreement between DES 3 2 pt and Planck than in DES Y1, despite the significantly improved precision of both. When combining DES 3 2 pt data with available baryon acoustic oscillation, redshift-space distortion, and type Ia supernovae data, we find p =0.34 . Combining all of these datasets with Planck CMB lensing yields joint parameter constraints of S8=0.81 2-0.008+0.008, m=0.30 6-0.005+0.004, h =0.68 0-0.003+0.004, and m<0.13 eV (95% C.L.) in CDM ; S8=0.81 2-0.008+0.008, m=0.30 2-0.006+0.006, h =0.68 7-0.007+0.006, and w =-1.03 1-0.027+0.030 in w CDM .
  187. Jenniskens, P., Moskovitz, N., 2022, eMetN, 7, 3, An outburst of Andromedids on November 28, 2021
    In addition to enhanced Andromedid (AND#0018) activity since November 20, 2021, we report here that an outburst of mainly faint meteors was detected over Northern America by northern hemisphere networks of the CAMS video orbit survey on November 28. The outburst was centered on solar longitude 245.887 0.007 (05h18m 0h10m UTC) and had a Full Width at Half Maximum of 4.0 0.5 h. The mean magnitude was +1.6 and magnitude distribution index was 3.8 0.3.
  188. Aadland, E., Massey, P., Hillier, D., et al., 2022, ApJ, 924, 44, The Physical Parameters of Four WC-type Wolf-Rayet Stars in the Large Magellanic Cloud: Evidence of Evolution
    We present a spectral analysis of four Large Magellanic Cloud (LMC) WC-type Wolf-Rayet (WR) stars (BAT99-8, BAT99-9, BAT99-11, and BAT99-52) to shed light on two evolutionary questions surrounding massive stars. The first is: are WO-type WR stars more oxygen enriched than WC-type stars, indicating further chemical evolution, or are the strong high-excitation oxygen lines in WO-type stars an indication of higher temperatures. This study will act as a baseline for answering the question of where WO-type stars fall in WR evolution. Each star's spectrum, extending from 1100 to 25000 A, was modeled using CMFGEN to determine the star's physical properties such as luminosity, mass-loss rate, and chemical abundances. The oxygen abundance is a key evolutionary diagnostic, and with higher resolution data and an improved stellar atmosphere code, we found the oxygen abundance to be up to a factor of 5 lower than that of previous studies. The second evolutionary question revolves around the formation of WR stars: do they evolve by themselves or is a close companion star necessary for their formation? Using our derived physical parameters, we compared our results to the Geneva single-star evolutionary models and the Binary Population and Spectral Synthesis (BPASS) binary evolutionary models. We found that both the Geneva solar-metallicity models and BPASS LMC-metallicity models are in agreement with the four WC-type stars, while the Geneva LMC-metallicity models are not. Therefore, these four WC4 stars could have been formed either via binary or single-star evolution. * This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.
  189. Everett, S., Yanny, B., Kuropatkin, N., et al., (including Kuehn, K.), 2022, ApJS, 258, 15, Dark Energy Survey Year 3 Results: Measuring the Survey Transfer Function with Balrog
    We describe an updated calibration and diagnostic framework, Balrog, used to directly sample the selection and photometric biases of the Dark Energy Survey (DES) Year 3 (Y3) data set. We systematically inject onto the single-epoch images of a random 20% subset of the DES footprint an ensemble of nearly 30 million realistic galaxy models derived from DES Deep Field observations. These augmented images are analyzed in parallel with the original data to automatically inherit measurement systematics that are often too difficult to capture with generative models. The resulting object catalog is a Monte Carlo sampling of the DES transfer function and is used as a powerful diagnostic and calibration tool for a variety of DES Y3 science, particularly for the calibration of the photometric redshifts of distant "source" galaxies and magnification biases of nearer "lens" galaxies. The recovered Balrog injections are shown to closely match the photometric property distributions of the Y3 GOLD catalog, particularly in color, and capture the number density fluctuations from observing conditions of the real data within 1% for a typical galaxy sample. We find that Y3 colors are extremely well calibrated, typically within ~1-8 mmag, but for a small subset of objects, we detect significant magnitude biases correlated with large overestimates of the injected object size due to proximity effects and blending. We discuss approaches to extend the current methodology to capture more aspects of the transfer function and reach full coverage of the survey footprint for future analyses.
  190. Hartley, W., Choi, A., Amon, A., et al., (including Kuehn, K.), 2022, MNRAS, 509, 3547, Dark Energy Survey Year 3 Results: Deep Field optical + near-infrared images and catalogue
    We describe the Dark Energy Survey (DES) Deep Fields, a set of images and associated multiwavelength catalogue (ugrizJHKs) built from Dark Energy Camera (DECam) and Visible and Infrared Survey Telescope for Astronomy (VISTA) data. The DES Deep Fields comprise 11 fields (10 DES supernova fields plus COSMOS), with a total area of ~30 sq. deg. in ugriz bands and reaching a maximum i-band depth of 26.75 (AB, 10, 2 arcsec). We present a catalogue for the DES 3-yr cosmology analysis of those four fields with full 8-band coverage, totalling 5.88 sq. deg. after masking. Numbering 2.8 million objects (1.6 million post-masking), our catalogue is drawn from images coadded to consistent depths of r = 25.7, i = 25, and z = 24.3 mag. We use a new model-fitting code, built upon established methods, to deblend sources and ensure consistent colours across the u-band to Ks-band wavelength range. We further detail the tight control we maintain over the point-spread function modelling required for the model fitting, astrometry and consistency of photometry between the four fields. The catalogue allows us to perform a careful star-galaxy separation and produces excellent photometric redshift performance (NMAD = 0.023 at i < 23). The Deep-Fields catalogue will be made available as part of the cosmology data products release, following the completion of the DES 3-yr weak lensing and galaxy clustering cosmology work.
  191. Penton, A., Malik, U., Davis, T., et al., (including Kuehn, K.), 2022, MNRAS, 509, 4008, OzDES reverberation mapping program: Lag recovery reliability for 6-yr C IV analysis
    We present the statistical methods that have been developed to analyse the OzDES reverberation mapping sample. To perform this statistical analysis we have created a suite of customizable simulations that mimic the characteristics of each source in the OzDES sample. These characteristics include: the variability in the photometric and spectroscopic light curves, the measurement uncertainties, and the observational cadence. By simulating the sources in the OzDES sample that contain the C IV emission line, we developed a set of criteria that rank the reliability of a recovered time-lag depending on the agreement between different recovery methods, the magnitude of the uncertainties, and the rate at which false positives were found in the simulations. These criteria were applied to simulated light curves and these results used to estimate the quality of the resulting Radius-Luminosity relation. We grade the results using three quality levels (gold, silver, and bronze). The input slope of the R-L relation was recovered within 1 for each of the three quality samples, with the gold standard having the lowest dispersion with a recovered a R-L relation slope of 0.454 0.016 with an input slope of 0.47. Future work will apply these methods to the entire OzDES sample of 771 AGN.
  192. Zacharegkas, G., Chang, C., Prat, J., et al., (including Kuehn, K.), 2022, MNRAS, 509, 3119, Dark Energy Survey Year 3 results: galaxy-halo connection from galaxy-galaxy lensing
    Galaxy-galaxy lensing is a powerful probe of the connection between galaxies and their host dark matter haloes, which is important both for galaxy evolution and cosmology. We extend the measurement and modelling of the galaxy-galaxy lensing signal in the recent Dark Energy Survey Year 3 cosmology analysis to the highly non-linear scales (~100 kpc). This extension enables us to study the galaxy-halo connection via a Halo Occupation Distribution (HOD) framework for the two lens samples used in the cosmology analysis: a luminous red galaxy sample (REDMAGIC) and a magnitude-limited galaxy sample (MAGLIM). We find that REDMAGIC (MAGLIM) galaxies typically live in dark matter haloes of mass log10(Mh/M) 13.7 which is roughly constant over redshift (13.3-13.5 depending on redshift). We constrain these masses to ${\sim}15{{\ \rm per\ cent}}$, approximately 1.5 times improvement over the previous work. We also constrain the linear galaxy bias more than five times better than what is inferred by the cosmological scales only. We find the satellite fraction for REDMAGIC (MAGLIM) to be ~0.1-0.2 (0.1-0.3) with no clear trend in redshift. Our constraints on these halo properties are broadly consistent with other available estimates from previous work, large-scale constraints, and simulations. The framework built in this paper will be used for future HOD studies with other galaxy samples and extensions for cosmological analyses.
  193. Lee, S., Troxel, M., Choi, A., et al., (including Kuehn, K.), 2022, MNRAS, 509, 2033, Galaxy-galaxy lensing with the DES-CMASS catalogue: measurement and constraints on the galaxy-matter cross-correlation
    The DMASS sample is a photometric sample from the DES Year 1 data set designed to replicate the properties of the CMASS sample from BOSS, in support of a joint analysis of DES and BOSS beyond the small overlapping area. In this paper, we present the measurement of galaxy-galaxy lensing using the DMASS sample as gravitational lenses in the DES Y1 imaging data. We test a number of potential systematics that can bias the galaxy-galaxy lensing signal, including those from shear estimation, photometric redshifts, and observing conditions. After careful systematic tests, we obtain a highly significant detection of the galaxy-galaxy lensing signal, with total S/N = 25.7. With the measured signal, we assess the feasibility of using DMASS as gravitational lenses equivalent to CMASS, by estimating the galaxy-matter cross-correlation coefficient rcc. By jointly fitting the galaxy-galaxy lensing measurement with the galaxy clustering measurement from CMASS, we obtain $r_{\rm cc}=1.09^{+0.12}_{-0.11}$ for the scale cut of $4 \, h^{-1}{\rm \,\,Mpc}$ and $r_{\rm cc}=1.06^{+0.13}_{-0.12}$ for $12 \, h^{-1}{\rm \,\,Mpc}$ in fixed cosmology. By adding the angular galaxy clustering of DMASS, we obtain rcc = 1.06 0.10 for the scale cut of $4 \, h^{-1}{\rm \,\,Mpc}$ and rcc = 1.03 0.11 for $12 \, h^{-1}{\rm \,\,Mpc}$. The resulting values of rcc indicate that the lensing signal of DMASS is statistically consistent with the one that would have been measured if CMASS had populated the DES region within the given statistical uncertainty. The measurement of galaxy-galaxy lensing presented in this paper will serve as part of the data vector for the forthcoming cosmology analysis in preparation.
  194. Carnero Rosell, A., Rodriguez-Monroy, M., Crocce, M., et al., (including Kuehn, K.), 2022, MNRAS, 509, 778, Dark Energy Survey Year 3 results: galaxy sample for BAO measurement
    In this paper, we present and validate the galaxy sample used for the analysis of the baryon acoustic oscillation (BAO) signal in the Dark Energy Survey (DES) Y3 data. The definition is based on a colour and redshift-dependent magnitude cut optimized to select galaxies at redshifts higher than 0.5, while ensuring a high-quality determination. The sample covers ${\sim }\, 4100$ deg2to a depth of i = 22.3 (AB) at 10. It contains 7031 993 galaxies in the redshift range from $z$ = 0.6 to 1.1, with a mean effective redshift of 0.835. Redshifts are estimated with the machine learning algorithm DNF, and are validated using the VIPERS PDR2 sample. We find a mean redshift bias of $z_{\mathrm{bias}} {\sim }\, 0.01$ and a mean uncertainty, in units of 1 + $z$, of $\sigma _{68} {\sim }\, 0.03$. We evaluate the galaxy population of the sample, showing it is mostly built upon Elliptical to Sbc types. Furthermore, we find a low level of stellar contamination of $\lesssim 4{{\ \rm per\ cent}}$. We present the method used to mitigate the effect of spurious clustering coming from observing conditions and other large-scale systematics. We apply it to the BAO sample and calculate weights that are used to get a robust estimate of the galaxy clustering signal. This paper is one of a series dedicated to the analysis of the BAO signal in DES Y3. In the companion papers, we present the galaxy mock catalogues used to calibrate the analysis and the angular diameter distance constraints obtained through the fitting to the BAO scale.
  195. 194 publications and 2592 citations in 2022.

194 publications and 2592 citations total.