sun

Polarization modeling and predictions for DKIST part 2: application of the Berreman calculus to spectral polarization fringes of beamsplitters and crystal retarders

We outline polarization fringe predictions derived from an application of the Berreman calculus for the Daniel K. Inouye Solar Telescope (DKIST) retarder optics. The DKIST retarder baseline design used six crystals, single-layer antireflection …

Polarization modeling and predictions for DKIST part 2: application of the Berreman calculus to spectral polarization fringes of beamsplitters and crystal retarders

We outline polarization fringe predictions derived from a new application of the Berreman calculus for the Daniel K. Inouye Solar Telescope (DKIST) retarder optics. The DKIST retarder baseline design used 6 crystals, single layer anti-reflection …

Unusual Stokes V profiles during flaring activity of a delta sunspot

Aims: We analyze a set of full Stokes profile observations of the flaring active region NOAA 10808. The region was recorded with the Vector-Spectromagnetograph of the Synoptic Optical Long-term Investigations of the Sun facility. The active region …

Fast horizontal flows in a quiet sun MHD simulation and their spectroscopic signatures

Numerical simulations of solar surface convection have predicted the existence of supersonic horizontal flows in the photospheric granulation. Recently, the detection of such flows in data from the Hinode satellite was reported. We study supersonic …

Observations of solar scattering polarization at high spatial resolution

Context. The weak, turbulent magnetic fields that supposedly permeate most of the solar photosphere are difficult to observe, because the Zeeman effect is virtually blind to them. The Hanle effect, acting on the scattering polarization in suitable …

Inversions of High-Cadence SOLIS-VSM Stokes Observations

We have processed full-Stokes observations made with the SOLIS-VSM using Fe I 630.15 and Fe I 630.25 nm. The data have high spectral and temporal resolution, moderate spatial resolution, and large polarimetric sensitivity and accuracy. We use the …

Statistics of Convective Collapse Events in the Photosphere and Chromosphere Observed with the HINODE SOT

Convective collapse, a theoretically predicted process that intensifies existing weak magnetic fields in the solar atmosphere, was first directly observed in a single event by Nagata et al. (2008) using the high resolution Solar Optical Telescope …

Two Ways of Improving Stokes Inversions

Performing Stokes inversion on single pixels can be difficult due to seeing and instrumental smearing. We present two different techniques to improve Stokes inversions. The first method, REGIONS, is a code that finds pixels that are likely to contain …

Statistics of convective collapse events in the photosphere and chromosphere observed with the Hinode SOT

Convective collapse, a theoretically predicted process that intensifies existing weak magnetic fields in the solar atmosphere, was first directly observed in a single event by Nagata et al. (2008, ApJ, 677, L145) using the high resolution Solar …

Vector Magnetic Field Inversions of High Cadence SOLIS-VSM Data

We have processed full Stokes observations from the SOLIS VSM in the photospheric lines Fe I 630.15 nm and 630.25 nm. The data sets have high spectral and temporal resolution, moderate spatial resolution, and large polarimetric sensitivity and …