The Astrophysical Journal (Jan 2023)
A Tale of Two Disks: Mapping the Milky Way with the Final Data Release of APOGEE
- Julie Imig,
- Cathryn Price,
- Jon A. Holtzman,
- Alexander Stone-Martinez,
- Steven R. Majewski,
- David H. Weinberg,
- Jennifer A. Johnson,
- Carlos Allende Prieto,
- Rachael L. Beaton,
- Timothy C. Beers,
- Dmitry Bizyaev,
- Michael R. Blanton,
- Joel R. Brownstein,
- Katia Cunha,
- José G. Fernández-Trincado,
- Diane K. Feuillet,
- Sten Hasselquist,
- Christian R. Hayes,
- Henrik Jönsson,
- Richard R. Lane,
- Jianhui Lian,
- Szabolcs Mészáros,
- David L. Nidever,
- Annie C. Robin,
- Matthew Shetrone,
- Verne Smith,
- John C. Wilson
Affiliations
- Julie Imig
- ORCiD
- Department of Astronomy, New Mexico State University , P.O. Box 30001, MSC 4500, Las Cruces, NM 88033, USA
- Cathryn Price
- ORCiD
- Department of Astronomy, New Mexico State University , P.O. Box 30001, MSC 4500, Las Cruces, NM 88033, USA
- Jon A. Holtzman
- ORCiD
- Department of Astronomy, New Mexico State University , P.O. Box 30001, MSC 4500, Las Cruces, NM 88033, USA
- Alexander Stone-Martinez
- ORCiD
- Department of Astronomy, New Mexico State University , P.O. Box 30001, MSC 4500, Las Cruces, NM 88033, USA
- Steven R. Majewski
- ORCiD
- Department of Astronomy, University of Virginia , Charlottesville, VA 22904, USA
- David H. Weinberg
- ORCiD
- The Department of Astronomy and Center of Cosmology and Astro Particle Physics, The Ohio State University , Columbus, OH 43210, USA; Institute for Advanced Study , Princeton, NJ 08540, USA
- Jennifer A. Johnson
- ORCiD
- The Department of Astronomy and Center of Cosmology and Astro Particle Physics, The Ohio State University , Columbus, OH 43210, USA
- Carlos Allende Prieto
- ORCiD
- Instituto de Astrofísica de Canarias , E-38205 La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna , E-38206 La Laguna, Tenerife, Spain
- Rachael L. Beaton
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; Department of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USA; The Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA
- Timothy C. Beers
- ORCiD
- Department of Physics and Astronomy and JINA Center for the Evolution of the Elements, University of Notre Dame , Notre Dame, IN 46556, USA
- Dmitry Bizyaev
- ORCiD
- Apache Point Observatory and New Mexico State University , P.O. Box 59, Sunspot, NM 88349-0059, USA; Sternberg Astronomical Institute, Moscow State University , Moscow
- Michael R. Blanton
- ORCiD
- Center for Cosmology and Particle Physics, Department of Physics, 726 Broadway, Room 1005, New York University , New York, NY 10003, USA
- Joel R. Brownstein
- ORCiD
- Department of Physics and Astronomy, University of Utah , 115 S. 1400 E., Salt Lake City, UT 84112, USA
- Katia Cunha
- ORCiD
- Steward Observatory, University of Arizona , Tucson, AZ 85721, USA
- José G. Fernández-Trincado
- ORCiD
- Instituto de Astronomía, Universidad Católica del Norte , Av. Angamos 0610, Antofagasta, Chile
- Diane K. Feuillet
- ORCiD
- Lund Observatory , Department of Astronomy and Theoretical Physics, Box 43, SE-221 00 Lund, Sweden
- Sten Hasselquist
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- Christian R. Hayes
- ORCiD
- NRC Herzberg Astronomy and Astrophysics Research Centre , 5071 West Saanich Road, Victoria, B.C., V9E 2E7, Canada
- Henrik Jönsson
- ORCiD
- Materials Science and Applied Mathematics, Malmö University , SE-205 06 Malmö, Sweden
- Richard R. Lane
- ORCiD
- Centro de Investigación en Astronomía, Universidad Bernardo O’Higgins , Avenida Viel 1497, Santiago, Chile
- Jianhui Lian
- ORCiD
- South-Western Institute for Astronomy Research, Yunnan University , Kunming, Yunnan 650091, People’s Republic of China
- Szabolcs Mészáros
- ORCiD
- ELTE Eötvös Loránd University , Gothard Astrophysical Observatory, 9700 Szombathely, Szent Imre H. st. 112, Hungary; MTA-ELTE Lendület “Momentum” Milky Way Research Group , Hungary; MTA-ELTE Exoplanet Research Group , Szombathely, Szent Imre h.u. 112., H-9700, Hungary
- David L. Nidever
- ORCiD
- Department of Physics, Montana State University , P.O. Box 173840, Bozeman, MT 59717, USA
- Annie C. Robin
- ORCiD
- Institut UTINAM—UMR 6213—CNRS— University of Bourgogne Franche Comté , France, OSU THETA, 41bis avenue de l’Observatoire, F-25000, Besançon, France
- Matthew Shetrone
- ORCiD
- University of California Observatories , UC Santa Cruz, Santa Cruz, CA 95064, USA
- Verne Smith
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 North Cherry Avenue, Tucson, AZ 85719, USA
- John C. Wilson
- ORCiD
- Astronomy Department, University of Virginia , Charlottesville, VA 22901, USA
- DOI
- https://doi.org/10.3847/1538-4357/ace9b8
- Journal volume & issue
-
Vol. 954,
no. 2
p. 124
Abstract
We present new maps of the Milky Way disk showing the distribution of metallicity ([Fe/H]), α -element abundances ([Mg/Fe]), and stellar age, using a sample of 66,496 red giant stars from the final data release (DR17) of the Apache Point Observatory Galactic Evolution Experiment survey. We measure radial and vertical gradients, quantify the distribution functions for age and metallicity, and explore chemical clock relations across the Milky Way for the low- α disk, high- α disk, and total population independently. The low- α disk exhibits a negative radial metallicity gradient of −0.06 ± 0.001 dex kpc ^−1 , which flattens with distance from the midplane. The high- α disk shows a flat radial gradient in metallicity and age across nearly all locations of the disk. The age and metallicity distribution functions shift from negatively skewed in the inner Galaxy to positively skewed at large radius. Significant bimodality in the [Mg/Fe]–[Fe/H] plane and in the [Mg/Fe]–age relation persist across the entire disk. The age estimates have typical uncertainties of ∼0.15 in log(age) and may be subject to additional systematic errors, which impose limitations on conclusions drawn from this sample. Nevertheless, these results act as critical constraints on galactic evolution models, constraining which physical processes played a dominant role in the formation of the Milky Way disk. We discuss how radial migration predicts many of the observed trends near the solar neighborhood and in the outer disk, but an additional more dramatic evolution history, such as the multi-infall model or a merger event, is needed to explain the chemical and age bimodality elsewhere in the Galaxy.
Keywords
- Milky Way Galaxy
- Milky Way disk
- Galactic abundances
- Stellar ages
- Galaxy stellar content
- Galactic archaeology
