Program: GS-2012A-Q-76

Carbon-Enhanced Metal-Poor (CEMP) stars are of great astrophysical interest for a host of reasons. Although the majority (80%) of such stars are known to be associated with mass-transfer events from a companion star that has evolved to the AGB stage (the CEMP-s stars), 20% of these stars do not exhibit enhanced s-process elements (the CEMP-no stars), and hence may be associated with a variety of other carbon-production mechanisms in the early Universe. A list of previously unidentified candidate CEMP stars from the Hamburg/ESO prism survey has been compiled, based on the strength of a new extended CH G-band index. Follow-up spectroscopy for sample of 234 candidates was obtained with GEMINI and SOAR, results show that the majority of candidates possess prominent carbon absorption features at 4300A. We propose to acquire additional spectroscopic data for this sample of CEMP candidates, using GMOS-S observations. This will enable the identification of new CEMP stars over a wide range of [Fe/H], which includes representatives of the inner- and outer-halo populations, as well as the metal-weak thick disk and thick disk. Metallicities and carbon abundances for such stars will serve as probes of the stellar populations in the Galaxy and its nearby satellites.