The Astrophysical Journal (Jan 2024)
A Perspective on the Milky Way Bulge Bar as Seen from the Neutron-capture Elements Cerium and Neodymium with APOGEE
- J. V. Sales-Silva,
- K. Cunha,
- V. V. Smith,
- S. Daflon,
- D. Souto,
- R. Guerço,
- A. Queiroz,
- C. Chiappini,
- C. R. Hayes,
- T. Masseron,
- Sten Hasselquist,
- D. Horta,
- N. Prantzos,
- M. Zoccali,
- C. Allende Prieto,
- B. Barbuy,
- R. Beaton,
- D. Bizyaev,
- J. G. Fernández-Trincado,
- P. M. Frinchaboy,
- J. A. Holtzman,
- J. A. Johnson,
- Henrik Jönsson,
- S. R. Majewski,
- D. Minniti,
- D. L. Nidever,
- R. P. Schiavon,
- M. Schultheis,
- J. Sobeck,
- G. S. Stringfellow,
- G. Zasowski
Affiliations
- J. V. Sales-Silva
- ORCiD
- Observatório Nacional/MCTI , R. Gen. José Cristino, 77, 20921-400, Rio de Janeiro, Brazil ; [email protected], [email protected]
- K. Cunha
- ORCiD
- Observatório Nacional/MCTI , R. Gen. José Cristino, 77, 20921-400, Rio de Janeiro, Brazil ; [email protected], [email protected]; Steward Observatory, University of Arizona , Tucson, AZ 85719, USA
- V. V. Smith
- ORCiD
- NOIRLab , Tucson, AZ 85719, USA
- S. Daflon
- ORCiD
- Observatório Nacional/MCTI , R. Gen. José Cristino, 77, 20921-400, Rio de Janeiro, Brazil ; [email protected], [email protected]
- D. Souto
- ORCiD
- Departamento de Física, Universidade Federal de Sergipe , Av. Marechal Rondon, S/N, 49000-000 São Cristóvão, SE, Brazil
- R. Guerço
- ORCiD
- Observatório Nacional/MCTI , R. Gen. José Cristino, 77, 20921-400, Rio de Janeiro, Brazil ; [email protected], [email protected]
- A. Queiroz
- Instituto de Astrofísica de Canarias , E-38200 La Laguna, Tenerife, Spain
- C. Chiappini
- Leibniz-Institut für Astrophysik Potsdam (AIP) , An der Sternwarte 16, 14482 Potsdam, Germany
- C. R. Hayes
- ORCiD
- NRC Herzberg Astronomy and Astrophysics Research Centre , 5071 West Saanich Rd., Victoria, B.C., V9E 2E7 Canada
- T. Masseron
- ORCiD
- Instituto de Astrofísica de Canarias (IAC) , E-38205 La Laguna, Tenerife, Spain; Universidad de La Laguna (ULL) , Departamento de Astrofísica, 38206 La Laguna, Tenerife, Spain
- Sten Hasselquist
- Space Telescope Science Institute , Baltimore, MD, USA
- D. Horta
- Center for Computational Astrophysics, Flatiron Institute ,162 Fifth Ave., New York, NY 10010, USA
- N. Prantzos
- ORCiD
- Institute d’Astrophysique de Paris , UMR 7095 CNRS & Sorbonne Université, 98 bis Blvd Arago, Paris 75014 France
- M. Zoccali
- ORCiD
- Instituto de Astrofísica, Pontificia Universidad Católica de Chile , Vicunã Mackenna 4860, Macul, Casilla 306, Santiago 22, Chile; Millenium Institute of Astrophysics (MAS) , Nuncio Monseñor Sótero Sanz 100, Providencia, Santiago Chile
- C. Allende Prieto
- ORCiD
- Instituto de Astrofísica de Canarias (IAC) , E-38205 La Laguna, Tenerife, Spain; Universidad de La Laguna (ULL) , Departamento de Astrofísica, 38206 La Laguna, Tenerife, Spain
- B. Barbuy
- ORCiD
- Universidade de São Paulo, IAG, Rua do Matão 1226, Cidade Universitária , São Paulo 05508-090, Brazil
- R. Beaton
- Space Telescope Science Institute , Baltimore, MD, USA
- D. 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, Russia
- J. G. Fernández-Trincado
- Instituto de Astronomía, Universidad Católica del Norte , Av. Angamos 0610, Antofagasta, Chile
- P. M. Frinchaboy
- ORCiD
- Department of Physics & Astronomy, Texas Christian University , TCU Box 298840, Fort Worth, TX 76129, USA
- J. A. Holtzman
- ORCiD
- New Mexico State University , Las Cruces, NM 88003, USA
- J. A. Johnson
- The Department of Astronomy and Center of Cosmology and Astro Particle Physics, The Ohio State University , Columbus, OH 43210, USA
- Henrik Jönsson
- ORCiD
- Materials Science and Applied Mathematics, Malmö University , SE-205 06 Malmö, Sweden
- S. R. Majewski
- ORCiD
- Department of Astronomy, University of Virginia , Charlottesville, VA 22904-4325, USA
- D. Minniti
- ORCiD
- Departamento de Fisica, Universidade Federal de Santa Catarina , Trinidade 88040-900, Florianopolis, Brazil; Instituto de Astrofísica, Facultad de Ciencias Exactas, Universidad Andres Bello , Avenida Fernández Concha 700, Santiago, Chile; Vatican Observatory , I-V00120 Vatican City State, Italy
- D. L. Nidever
- ORCiD
- Department of Physics, Montana State University , P.O. Box 173840, Bozeman, MT 59717-3840, USA
- R. P. Schiavon
- ORCiD
- Astrophysics Research Institute, Liverpool John Moores University , Liverpool, L3 5RF, UK
- M. Schultheis
- ORCiD
- Université Côte d’Azur , Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
- J. Sobeck
- ORCiD
- Department of Astronomy, University of Washington , Box 351580, Seattle, WA 98195, USA
- G. S. Stringfellow
- ORCiD
- Center for Astrophysics and Space Astronomy, University of Colorado at Boulder , 389 UCB, Boulder, CO 80309-0389, USA
- G. Zasowski
- ORCiD
- Department of Physics and Astronomy, University of Utah , Salt Lake City, UT 84105, USA
- DOI
- https://doi.org/10.3847/1538-4357/ad28c2
- Journal volume & issue
-
Vol. 965,
no. 2
p. 119
Abstract
This study probes the chemical abundances of the neutron-capture elements cerium and neodymium in the inner Milky Way from an analysis of a sample of ∼2000 stars in the Galactic bulge bar spatially contained within ∣ X _Gal ∣ < 5 kpc, ∣ Y _Gal ∣ < 3.5 kpc, and ∣ Z _Gal ∣ < 1 kpc, and spanning metallicities between −2.0 ≲ [Fe/H] ≲ +0.5. We classify the sample stars into low- or high-[Mg/Fe] populations and find that, in general, values of [Ce/Fe] and [Nd/Fe] increase as the metallicity decreases for the low- and high-[Mg/Fe] populations. Ce abundances show a more complex variation across the metallicity range of our bulge-bar sample when compared to Nd, with the r -process dominating the production of neutron-capture elements in the high-[Mg/Fe] population ([Ce/Nd] < 0.0). We find a spatial chemical dependence of Ce and Nd abundances for our sample of bulge-bar stars, with low- and high-[Mg/Fe] populations displaying a distinct abundance distribution. In the region close to the center of the MW, the low-[Mg/Fe] population is dominated by stars with low [Ce/Fe], [Ce/Mg], [Nd/Mg], [Nd/Fe], and [Ce/Nd] ratios. The low [Ce/Nd] ratio indicates a significant contribution in this central region from r -process yields for the low-[Mg/Fe] population. The chemical pattern of the most metal-poor stars in our sample suggests an early chemical enrichment of the bulge dominated by yields from core-collapse supernovae and r -process astrophysical sites, such as magnetorotational supernovae.
Keywords
