Detailed abundance analysis of a metal-poor giant in the Galactic Center
  We report the first results from our program to examine the metallicity
distribution of the Milky Way nuclear star cluster connected to SgrA*, with the
goal of inferring the star formation and enrichment history of this system, as
well as its connection and relationship with the central 100 pc of the
bulge/bar system. We present the first high resolution (R~24,000), detailed
abundance analysis of a K=10.2 metal-poor, alpha-enhanced red giant projected
at 1.5 pc from the Galactic Center, using NIRSPEC on Keck II. A careful
analysis of the dynamics and color of the star locates it at about 26 pc
line-of-sight distance in front of the nuclear cluster. It probably belongs to
one of the nuclear components (cluster or disk), not to the bar-bulge or
classical disk. A detailed spectroscopic synthesis, using a new linelist in the
K band, finds [Fe/H]~-1.0 and [alpha/Fe]~+0.4, consistent with stars of similar
metallicity in the bulge. As known giants with comparable [Fe/H] and alpha
enhancement are old, we conclude that this star is most likely to be a
representative of the ~10 Gyr old population. This is also the most metal poor
confirmed red giant yet discovered in vicinity of the nuclear cluster of the
Galactic Center. We consider recent reports in the literature of a surprisingly
large number of metal poor giants in the Galactic Center, but the reported
gravities of log g ~4 for these stars calls into question their reported
metallicities.
