APOGEE DR14/DR15 Abundances in the Inner Milky Way

We present an overview of the distributions of 11 elemental abundances in the Milky Way's (MW) inner regions, as traced by APOGEE stars released as part of the Sloan Digital Sky Survey Data Release. 14/15 (DR14/DR15), including O, Mg, Si, Ca, Cr, Mn, Co, Ni, Na, Al, and K. This sample spans similar to 4000 stars with R-GC <= 4.0 kpc, enabling the most comprehensive study to date of these abundances and their variations within the innermost few kiloparsecs of the MW. We describe the observed abundance patterns ([X/Fe]-[Fe/H]), compare to previous literature results and to patterns in stars at the solar Galactocentric radius (R-GC), and discuss possible trends with DR14/DR15 effective temperatures. We find that the position of the [Mg/Fe]-[Fe/H] "knee" is nearly constant with R-GC, indicating a well-mixed star-forming medium or high levels of radial migration in the early inner Galaxy. We quantify the linear correlation between pairs of elements in different subsamples of stars and find that these relationships vary; some abundance correlations are very similar between the alpha-rich and alpha-poor stars, but others differ significantly, suggesting variations in the metallicity dependencies of certain supernova yields. These empirical trends will form the basis for more detailed future explorations and for the refinement of model comparison metrics. That the inner MW abundances appear dominated by a single chemical evolutionary track and that they extend to such high metallicities underscore the unique importance of this part of the Galaxy for constraining the ingredients of chemical evolution modeling and for improving our understanding of the evolution of the Galaxy as a whole.Lasker Data Science Research Fellowship; Space Telescope Science Institute in Baltimore, MD, USA; Programme National de Cosmologie et Galaxies (PNCG) of CNRS/INSU, France [PHY 14-30152]; U.S. National Science Foundation; Crafoord Foundation; Stiftelsen Olle Engkvist Byggmastare; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy Office of Science; University of Arizona; Brazilian Participation Group; Brookhaven National Laboratory; Carnegie Mellon University, University of Florida; French Participation Group; German Participation Group; Harvard University; Instituto de Astrofisica de Canarias; 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; Pennsylvania State University, University of Portsmouth; Princeton University; Spanish Participation Group, University of Tokyo, University of Utah; Yale University; Center for High-Performance Computing at the University of Utah; Carnegie Institution for Science; Chilean Participation Group; Harvard-Smithsonian Center for Astrophysics; Kavli Institute for the Physics and Mathematics of the Universe (IPMU)/University of Tokyo; Max-Planck-Institut fur Astrophysik (MPA Garching); Max-Planck-Institut fur Extraterrestrische Physik (MPE); New Mexico State University, New York University, University of Notre Dame, Observatario Nacional/MCTI; Shanghai Astronomical Observatory, United Kingdom Participation Group; E-Science and Supercomputing Group at Leibniz Institute for Astrophysics Potsdam (AIP)This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu