The recent identification of brown dwarfs in open clusters and in the solar neighborhood has been followed by the discovery of young brown dwarfs in regions of star formation. These discoveries are exciting in their own right, however, the number of known brown dwarfs remains small. A collection of substellar objects in a star cluster will be studied to investigate how brown dwarfs form, the properties of their circumstellar disks, and their contribution to the total mass of the stellar cluster. The regions of star formation are prime targets for brown dwarf searches because the substellar objects are localized in a small region and because they are much brighter in their youth. In addition, extinction by the parent molecular cloud screens out background stars that could masquerade as young brown dwarfs. Due to the presence of dust in these regions, infrared techniques are necessary for the study of populations of young brown dwarfs.
Near-infrared wavelength imaging and spectroscopy will be used to identify and characterize populations of brown dwarfs in the nearby rho Ophiuchi and NGC 1333 star-forming clouds. Infrared imaging will be used to form a sample of brown dwarf candidates and low-resolution infrared spectroscopy will be used to identify candidates with cool photospheres. The spectral types of the stars will be determined by measuring the depths of water vapor bands in the data in comparison to a grid of M dwarf spectral standards. By deriving bolometric luminosities and effective temperatures from these data, we can compare them with theoretical models to determine their masses and ages. A preliminary study in the rho Ophiuchi cloud has refined the techniques and identified six probable brown dwarfs and another five objects at the stellar/substellar boundary.
