Program: GS-2006A-Q-55
Title: | A Spectroscopic Study of Young 5-100 M$_{\rm J}$ Objects in Lupus and Cham II |
PI: | Daniel Jaffe |
Co-I(s): | Katelyn Allers, Greg Doppmann |
Abstract
By studying brown dwarfs when they are young and bright, we can investigate
the nature of objects with extremely low masses and test
our understanding of star formation and protostellar evolution at one
extreme of the mass range.
We have used very deep IJHK imaging combined with Spitzer 3.5-24 $\mu$m
observations to identify a sample of young brown dwarfs in nearby star
forming regions. The presence of circum-object disks confirms the youth
of these sources and their association with the parent clouds. The objects
have luminosities from 10$^{-4}$ to 10$^{-1}$ L$_{\odot}$ with a substantial
fraction at or below the lowest luminosities previously reported for
young brown dwarfs. For ages of 1-3$\times 10^6$ years, the lowest mass
objects are $\sim$2M$_J$ and half are below the deuterium burning limit.
We will use GNIRS to take R=1700 JHK spectra of a subsample of these
young brown dwarfs. We will use the spectroscopic results to produce a
low-gravity sequence for L-type objects. We will test models of young
BD atmospheres in a regime where uncertain molecular opacities and the
effects of dust settling have not been confronted with observations.
We will use the spectroscopic and photometric data for the whole sample
to place these young brown dwarfs in an HR diagram to investigate the
evolutionary state of the extended low mass population in star forming
clouds.