期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 499, 期 1, 页码 1037-1057出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/staa2807
关键词
infrared: stars; stars: fundamental parameters; stars: abundances; Galaxy: bulge; Galaxy: structure; Galaxy: stellar content
资金
- FONDECYT [3180203, 3180210]
- Chilean Centro de Excelencia en Astrofisica y Tecnologias Afines (CATA) BASAL [AFB170002]
- Chilean Centro de Excelencia en Astrofisica y Tecnologias Afines (CATA) BASAL grant [AFB-170002]
- proyecto FONDECYT Regular [1170121]
- Direccion de Investigacion y Desarrollo de la Universidad de La Serena through the Programa de Incentivo a la Investigacion de Academicos (PIA-DIDULS)
- State Research Agency (AEI) of the Spanish Ministry of Science, Innovation and Universities (MCIU)
- European Regional Development Fund (FEDER) [AYA201788254-P]
- Becas Iberoamerica Investigador 2019, Banco Santander Chile
- FONDECYT Regular [1181797]
- Max Planck Society
- DFG [CH1188/21]
- ChETEC COST Action - COST (European Cooperation in Science and Technology) [CA16117]
- Alfred P. Sloan Foundation
- U.S. Department of Energy Office of Science
- Center for High-Performance Computing at the University of Utah
- Carnegie Mellon University
- Chilean Participation Group
- French Participation Group
- Harvard-Smithsonian Center for Astrophysics
- Instituto de Astrofisica de Canarias
- Johns Hopkins University
- Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo
- Korean Participation Group
- Lawrence Berkeley National Laboratory
- Leibniz Institut fur Astrophysik Potsdam (AIP)
- Max-Planck-Institut fur Astronomie (MPIA Heidelberg)
- Max-Planck-Institut fur Astrophysik (MPA Garching)
- Max-Planck-Institut fur Extraterrestrische Physik (MPE)
- National Astronomical Observatories of China
- New Mexico State University
- New York University
- University of Notre Dame
- Observatario Nacional/MCTI
- Ohio State University
- Pennsylvania State University
- Shanghai Astronomical Observatory
- United Kingdom Participation Group
- Universidad Nacional Autonoma de Mexico
- University of Arizona
- University of Colorado Boulder
- University of Oxford
- University of Portsmouth
- University of Utah
- University of Virginia
- University of Washington
- University of Wisconsin
- Vanderbilt University
- Yale University
- Brazilian Participation Group
- Carnegie Institution for Science
We use data of similar to 13 000 stars from the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment survey to study the shape of the bulge metallicity distribution function (MDF) within the region vertical bar l vertical bar <= 11 degrees and vertical bar b vertical bar = 13 degrees, and spatially constrained to R-GC <= 3.5 kpc. We apply Gaussian mixture modelling and non-negative matrix factorization decomposition techniques to identify the optimal number and the properties of MDF components. We find that the shape and spatial variations of the MDF (at [Fe/H] >= -1 dex) are well represented as a smoothly varying contribution of three overlapping components located at [Fe/H] = +0.32, -0.17, and -0.66 dex. The bimodal MDF found in previous studies is in agreement with our trimodal assessment once the limitations in sample size and individual measurement errors are taken into account. The shape of the MDF and its correlations with kinematics reveal different spatial distributions and kinematical structure for the three components co-existing in the bulge region. We confirm the consensus physical interpretation of metal-rich stars as associated with the secularly evolved disc into a boxy/peanut X-shape bar. On the other hand, metal-intermediate stars could be the product of in-situ formation at high redshift in a gas-rich environment characterized by violent and fast star formation. This interpretation would help us to link a present-day structure with those observed in formation in the centre of high-redshift galaxies. Finally, metal-poor stars may correspond to the metal-rich tail of the population sampled at lower metallicity from the study of RR Lyrae stars. Conversely, they could be associated with the metal-poor tail of the early thick disc.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据