APOGEE DR14/DR15 Abundances in the Inner Milky Way

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Abstract

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 ∼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 α-rich and α-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.

Detaljer

Författare
  • G. Zasowski
  • M. Schultheis
  • S. Hasselquist
  • K. Cunha
  • J. Sobeck
  • J. A. Johnson
  • A. Rojas-Arriagada
  • S. R. Majewski
  • B. H. Andrews
  • H. Jönsson
  • T. C. Beers
  • S. D. Chojnowski
  • P. M. Frinchaboy
  • J. A. Holtzman
  • D. Minniti
  • D. L. Nidever
  • C. Nitschelm
Enheter & grupper
Externa organisationer
  • University of Utah
  • Côte d'Azur Observatory
  • New Mexico State University
  • University of Arizona
  • National Observatory Brazil
  • University of Washington
  • Ohio State University
  • Pontifical Catholic University of Chile
  • Millennium Institute of Astrophysics
  • University of Virginia
  • University of Pittsburgh
  • University of Notre Dame
  • Texas Christian University
  • National Optical Astronomy Observatory
  • Montana State University
  • University of Antofagasta
  • University of Côte d'Azur
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Astronomi, astrofysik och kosmologi

Nyckelord

Originalspråkengelska
Artikelnummer138
TidskriftAstrophysical Journal
Volym870
Utgåva nummer2
StatusPublished - 2019 jan 16
PublikationskategoriForskning
Peer review utfördJa