Thorsbro, B.B.ThorsbroRyde, N.N.RydeRich, R. M.R. M.RichSchultheis, M.M.SchultheisRenaud, F.F.RenaudSpitoni, E.E.SpitoniFritz, T. K.T. K.FritzMastrobuono-Battisti, A.A.Mastrobuono-BattistiORIGLIA, LiviaLiviaORIGLIAMatteucci, F.F.MatteucciSchödel, R.R.Schödel2025-03-102025-03-1020200004-637Xhttp://hdl.handle.net/20.500.12386/36589We present a detailed study of the composition of 20 M giants in the Galactic center with 15 of them confirmed to be in the nuclear star cluster. As a control sample we have also observed 7 M giants in the Milky Way disk with similar stellar parameters. All 27 stars are observed using the NIRSPEC spectrograph on the KECK II telescope in the K-band at a resolving power of R = 23,000. We report the first silicon abundance trends versus [Fe/H] for stars in the Galactic center. While finding a disk/bulge-like trend at subsolar metallicities, we find that [Si/Fe] is enhanced at supersolar metallicities. We speculate on possible enrichment scenarios to explain such a trend. However, the sample size is modest and the result needs to be confirmed by additional measurements of silicon and other α-elements. We also derive a new distribution of [Fe/H] and find the most metal-rich stars at [Fe/H] = +0.5 dex, confirming our earlier conclusions that the Galactic center hosts no stars with extreme chemical compositions.STAMPAenArticle10.3847/1538-4357/ab82262-s2.0-85088388608https://api.elsevier.com/content/abstract/scopus_id/85088388608https://iopscience.iop.org/article/10.3847/1538-4357/ab82262020ApJ...894...26TFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation