Published 2024
| Version v1
Journal article
A Perspective on the Milky Way Bulge Bar as Seen from the Neutron-capture Elements Cerium and Neodymium with APOGEE
Creators
- Sales-Silva, J
- Cunha, K.
- Smith, V
- Daflon, S.
- Souto, D.
- Guerço, R.
- Queiroz, A.
- Chiappini, C.
- Hayes, C
- Masseron, T.
- Hasselquist, Sten
- Horta, D.
- Prantzos, N.
- Zoccali, M.
- Allende Prieto, C.
- Barbuy, B.
- Beaton, R.
- Bizyaev, D.
- Fernández-Trincado, J
- Frinchaboy, P
- Holtzman, J
- Johnson, J
- Jönsson, Henrik
- Majewski, S
- Minniti, D.
- Nidever, D
- Schiavon, R
- Schultheis, M.
- Sobeck, J.
- Stringfellow, G
- Zasowski, G.
Contributors
Others:
- Institut d'Astrophysique de Paris (IAP) ; Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
- Joseph Louis LAGRANGE (LAGRANGE) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur ; Université Côte d'Azur (UniCA)-Université Côte d'Azur (UniCA)-Centre National de la Recherche Scientifique (CNRS)
Description
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 corecollapse supernovae and r-process astrophysical sites, such as magnetorotational supernovae.
Abstract
International audienceAdditional details
Identifiers
- URL
- https://hal.science/hal-04795510
- URN
- urn:oai:HAL:hal-04795510v1