Spectroscopy of a Young Brown Dwarf
Session 58 -- Outflows and the Low Mass IMF
Oral presentation, Thursday, January 13, 10:15-11:45, Salon V Room (Crystal Gateway)

[58.05] Spectroscopy of a Young Brown Dwarf

G. H. Rieke, D. M. Williams (Steward Observatory), F. Comer\'{o}n (University of Barcelona)

We report a spectrum at 2$\mu$m of a brown dwarf candidate in the rho Ophiuchi star forming cluster. This object is source 2320.8-1721 in the study of Comer\'{o}n et. al. (ApJ 416, 185), who suggested that it is a young brown dwarf on the basis of modeling its photometric colors and luminosity. Its spectrum shows extremely strong Na absorption, as well as features due to FeI and CO. Compared with similar spectra of a suite of very cool evolved M dwarfs, the spectrum shows that the near infrared flux comes from the photosphere of an extremely cool object. We use the new temperature constraints for the object and repeat the photometric modeling with updated brown dwarf isochrones. The results strongly support the identification of 2323.8-1721 as a young brown dwarf, of mass approximately 0.02 to 0.03 solar masses.