NOAO >   Observing Info >   Approved Programs >   2005A-0282

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Proposal Information for 2005A-0282


PI: John Robinson, University of Missouri-St. Louis, johnr@newton.umsl.edu
Address: Department of Physics and Astronomy, 8001 Natural Bridge Road, St. Louis, MO 63121, USA

CoI: Bruce Wilking, University of Missouri-St. Louis
CoI: Michael Meyer, University of Arizona

Title: Unveiling the Low Mass IMF in the Rho Ophiuchi Cloud

Abstract: We propose to obtain spectra for 105 candidate association members in the vicinity of the Rho Oph dark cloud. When combined with our previous lower resolution HYDRA observations for 130 stars, and our medium resolution HYDRA observations for 73 stars, we will have a large, unbiased sample of low mass association members that is complete for all objects above the hydrogen-burning limit with an age of 10 Myr or less and A_v < 2.5 mag. It will extend into the sub-stellar regime for younger, less-extincted objects. Medium resolution spectra obtained with HYDRA from 6300-7700 \AA will enable us to; i) measure the Li equivalent width (6707 \AA) to identify association membership, ii) determine surface gravities using the CaH absorption band (6975 \AA), and iii) estimate spectral types (and thus photospheric temperatures) crucial for placing these objects in the H-R diagram and determining their ages and masses. We will use this unbiased sample to investigate disk l!


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NOAO >   Observing Info >   Approved Programs >   2005A-0282

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