First Results From The BOSS Ultracool Dwarf (BUD) Sample
Abstract
We introduce the BOSS Ultracool Dwarf (BUD) sample of 12,085 M7-L8 dwarfs selected from the Sloan Digital Sky Survey (SDSS) photometry and spectroscopy. The BUD sample includes ultracool dwarfs selected from the SDSS seventh data release in addition to new dwarfs from the Baryon Oscillation Sky Survey (BOSS). We present the izJHKW1W2W3 color locus from a cross-match between the BUD sample and the 2MASS and WISE catalogs. In addition to colors, we also examine chromospheric activity based on the presence and strength of Hα emission. When we restrict our activity search to spectra with S/N > 3 in the region surrounding Hα, we find that over 80% of nearby early-L dwarfs are active. The fraction of active ultracool dwarfs is larger closer to the galactic plane, indicating that ultracool dwarfs follow an age activity relationship similar to more massive M dwarfs.
- Publication:
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American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22115821S