Formación de Estrellas de Muy Baja Masa y de Enanas Marrones

M. GÓMEZ

Buenos Aires

Congreso; 45 Reunión de la Asociación Argentina de Astronomía; 2002

Instituto de Astronomía y Física del Espacio (IAFE) - Asociación Argentina de Astronomia

The star formation process in the southern Chamaeleon I dark cloud is described. This region harbors about 150 young stellar objects with masses less than 2.5 M_Sun. Several surveys in the region have detected many faint (K about 12--16) infrared color excess candidate members of the cloud. These objects are likely to have very low masses down to the sub-stellar regimen (i.e., objects with masses < 0.08 M_Sun). In this contribution we discuss recent results of a spectroscopic survey in JHK of about 50 of the brightest (K < 12) potential young stars. We estimate masses and ages and then analyze their contribution to the initial mass function (IMF) of the cloud. The great majority of the new objects have sub-solar masses and only two candidates turned out to have masses below the H-burning limit. This result suggests that the very faint candidate members with K > 12--16 may contain at least part of the missing population cloud with masses in the sub-stellar regimen. Near-infrared spectra are required to test this suggestion.