@article{1184e51d355c4bd0a20a81e12c54b955,
title = "Evidence for a metal-poor population in the inner Galactic bulge",
abstract = "The inner Galactic bulge has, until recently, been avoided in chemical evolution studies because of extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), for the first time allow the measurement of metallicities in the inner region of our Galaxy. We study metallicities of 33 K/M giants situated in the Galactic center region from observations obtained with the APOGEE survey. We selected K/M giants with reliable stellar parameters from the APOGEE/ASPCAP pipeline. Distances, interstellar extinction values, and radial velocities were checked to confirm that these stars are indeed situated in the inner Galactic bulge. We find a metal-rich population centered at [M/H] = +0.4 dex, in agreement with earlier studies of other bulge regions, but we also discovered a peak at low metallicity around [M/H] =-1.0 dex. This finding suggests the presence of a metal-poor population, which has not previously been detected in the central region. Our results indicate a dominant metal-rich population with a metal-poor component that is enhanced in the α-elements. This metal-poor population may be associated with the classical bulge and a fast formation scenario.",
keywords = "Galaxy: bulge, Galaxy: stellar content, Stars: abundances, Stars: fundamental parameters",
author = "M. Schultheis and K. Cunha and G. Zasowski and {Garci{\'a} P{\'e}rez}, {A. E.} and K. Sellgren and V. Smith and Garci{\'a}-Hern{\'a}ndez, {D. A.} and O. Zamora and Fritz, {T. K.} and F. Anders and {Allende Prieto}, C. and D. Bizyaev and K. Kinemuchi and K. Pan and E. Malanushenko and V. Malanushenko and Shetrone, {M. D.}",
note = "Funding Information: Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the US Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. Publisher Copyright: {\textcopyright} 2015 ESO.",
year = "2015",
month = dec,
day = "1",
doi = "10.1051/0004-6361/201527027",
language = "English (US)",
volume = "584",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
}