Brown Dwarfs and the TW Hydrae Association

I report the results of a survey for low-mass (0.030 <~ M <~ 0.013 M_solar)brown dwarfs in the direction of the TW Hya association using 2MASS. Two late-Mdwarfs show signs of low surface gravity and are strong candidates to be young,very-low-mass (M ~ 0.025 M_solar) brown dwarfs related to the TW Hyaassociation. 2MASSW J1207334-393254 is particularly notable for its strong Halpha emission. The number of detected brown dwarfs is consistent with thesubstellar mass function in richer star formation environments. Newlyidentified late-M and L dwarfs in the field are also discussed. Unusual objectsinclude an L dwarf with strong H alpha emission, a possible wide M8/M9 triplesystem, and a possible L dwarf companion to an LHS star.Comment: Accepted to Ap.J., 22 page