Ryde, N.N.RydeFritz, T. K.T. K.FritzRich, R. M.R. M.RichThorsbro, B.B.ThorsbroSchultheis, M.M.SchultheisORIGLIA, LiviaLiviaORIGLIAChatzopoulos, S.S.Chatzopoulos2020-07-032020-07-0320160004-637Xhttp://hdl.handle.net/20.500.12386/26304We report the first results from our program to examine the metallicity distribution of the Milky Way nuclear star cluster connected to Sgr A*, 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}<SUB>-16</SUB><SUP>+54</SUP> 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 line list in the K band, finds [Fe/H] ∼ -1.0 and [α/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 the 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 gravity of {log}g∼ 4 for these stars calls into question their reported metallicities.STAMPAenArticle10.3847/0004-637X/831/1/402-s2.0-84994275468000387229300003https://iopscience.iop.org/article/10.3847/0004-637X/831/1/402016ApJ...831...40RFIS/05 - ASTRONOMIA E ASTROFISICA