TY - JOUR
T1 - The Bulge Metallicity Distribution from the APOGEE Survey
AU - García Pérez, Ana E.
AU - Ness, Melissa
AU - Robin, Annie C.
AU - Martinez-Valpuesta, Inma
AU - Sobeck, Jennifer
AU - Zasowski, Gail
AU - Majewski, Steven R.
AU - Bovy, Jo
AU - Prieto, Carlos Allende
AU - Cunha, Katia
AU - Girardi, Léo
AU - Mészáros, Szabolcs
AU - Nidever, David
AU - Schiavon, Ricardo P.
AU - Schultheis, Mathias
AU - Shetrone, Matthew
AU - Smith, Verne V.
N1 - Funding Information:
Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III website ishttp://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, University of Cambridge, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofísica 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.
Funding Information:
Support for A.E.G.P. was provided by SDSS-III/APOGEE. C.A.P. is grateful for support from MINECO for this research through grant AYA2014-56359-P. Sz.M. has been supported by the Premium Postdoctoral Research Program of the Hungarian Academy of Sciences, and by the Hungarian NKFI Grants K-119517 of the Hungarian National Research, Development and Innovation Office. BGM simulations were executed on computers from the Utinam Institute of the Université de Franche-Comté supported by the Région de Franche-Comté and Institut des Sciences de l’Univers (INSU).
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved..
PY - 2018/1/10
Y1 - 2018/1/10
N2 - The Apache Point Observatory Galactic Evolution Experiment (APOGEE) provides spectroscopic information of regions of the inner Milky Way, which are inaccessible to optical surveys. We present the first large study of the metallicity distribution of the innermost Galactic regions based on high-quality measurements for 7545 red giant stars within 4.5 kpc of the Galactic center, with the goal to shed light on the structure and origin of the Galactic bulge. Stellar metallicities are found, through multiple Gaussian decompositions, to be distributed in several components, which is indicative of the presence of various stellar populations such as the bar or the thin and the thick disks. Super-solar ([Fe/H] = +0.32) and solar ([Fe/H] = +0.00) metallicity components, tentatively associated with the thin disk and the Galactic bar, respectively, seem to be major contributors near the midplane. A solar-metallicity component extends outwards in the midplane but is not observed in the innermost regions. The central regions (within 3 kpc of the Galactic center) reveal, on the other hand, the presence of a significant metal-poor population ([Fe/H] = -0.46), tentatively associated with the thick disk, which becomes the dominant component far from the midplane (|Z| ≥ +0.75 kpc). Varying contributions from these different components produce a transition region at +0.5 kpc ≤|Z|≤ +1.0Kpc, characterized by a significant vertical metallicity gradient.
AB - The Apache Point Observatory Galactic Evolution Experiment (APOGEE) provides spectroscopic information of regions of the inner Milky Way, which are inaccessible to optical surveys. We present the first large study of the metallicity distribution of the innermost Galactic regions based on high-quality measurements for 7545 red giant stars within 4.5 kpc of the Galactic center, with the goal to shed light on the structure and origin of the Galactic bulge. Stellar metallicities are found, through multiple Gaussian decompositions, to be distributed in several components, which is indicative of the presence of various stellar populations such as the bar or the thin and the thick disks. Super-solar ([Fe/H] = +0.32) and solar ([Fe/H] = +0.00) metallicity components, tentatively associated with the thin disk and the Galactic bar, respectively, seem to be major contributors near the midplane. A solar-metallicity component extends outwards in the midplane but is not observed in the innermost regions. The central regions (within 3 kpc of the Galactic center) reveal, on the other hand, the presence of a significant metal-poor population ([Fe/H] = -0.46), tentatively associated with the thick disk, which becomes the dominant component far from the midplane (|Z| ≥ +0.75 kpc). Varying contributions from these different components produce a transition region at +0.5 kpc ≤|Z|≤ +1.0Kpc, characterized by a significant vertical metallicity gradient.
KW - Galaxy: bulge
KW - Galaxy: structure
KW - stars: abundances
KW - stars: atmospheres
UR - http://www.scopus.com/inward/record.url?scp=85040704233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85040704233&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aa9d88
DO - 10.3847/1538-4357/aa9d88
M3 - Article
AN - SCOPUS:85040704233
VL - 852
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 91
ER -