Name/Affiliation: Sarah E. Logsdon (UCLA)
Near-Infrared Imaging of T and Y Dwarfs with MOSFIRE
We present the results of two MOSFIRE (the Multi-Object Spectrometer For Infra-Red Exploration) imaging campaigns geared to reveal and characterize late-type brown dwarfs and brown dwarf candidates. MOSFIRE, on the Keck I telescope, is not only a multi-object spectrometer, but is also a wide-field imager (6.14’x6.14’ FOV) with the ability to reach a limiting magnitude of J~23.5 in 15 minutes. This makes imaging with MOSFIRE a powerful tool for following up faint, late-type brown dwarfs. The first of our two imaging campaigns was designed to calibrate MOSFIRE’s medium band H1 and H2 filters that are optimized for methane imaging. The H1 and H2 filters split the traditional H band, isolating the strong 1.67 µm methane absorption that is found in T and Y dwarfs, and giving these dwarfs uniquely blue H1-H2 colors. Here we present the H1-H2 color indices for 25 T5-Y0 brown dwarfs and discuss color trends and the utility of these filters for further brown dwarf studies at the latest spectral types. The second campaign has been designed to follow-up extremely red brown dwarf candidates from AllWISE by measuring their J-H colors and on-sky motion. We present preliminary results from this campaign and discuss the astrometric capabilities of MOSFIRE.