| Title: |
A Perspective on the Milky Way Bulge Bar as Seen from the Neutron-capture Elements Cerium and Neodymium with APOGEE |
| Authors: |
Sales-Silva, JV; Cunha, K; Smith, VV; Daflon, S; Souto, D; Guerco, R; Queiroz, A; Chiappini, C; Hayes, CR; Masseron, T; Hasselquist, S; Horta, D; Prantzos, N; Zoccali, M; Allende Prieto, C; Barbuy, B; Beaton, R; Bizyaev, D; Fernandez-Trincado, JG; Frinchaboy, PM; Holtzman, JA; Johnson, JA; Joensson, H; Majewski, SR; Minniti, D; Nidever, DL; Schiavon, RP; Schultheis, M; Sobeck, J; Stringfellow, GS; Zasowski, G |
| Publisher Information: |
American Astronomical Society |
| Publication Year: |
2024 |
| Collection: |
Liverpool John Moores University: LJMU Research Online |
| Subject Terms: |
QB Astronomy; QC Physics |
| 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 ∣XGal∣ < 5 kpc, ∣YGal∣ < 3.5 kpc, and ∣ZGal∣ < 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. |
| Document Type: |
article in journal/newspaper |
| File Description: |
text |
| Language: |
English |
| ISSN: |
0004-637X |
| Relation: |
https://researchonline.ljmu.ac.uk/id/eprint/24616/1/A%20Perspective%20on%20the%20Milky%20Way%20Bulge%20Bar%20as%20Seen%20from%20the%20Neutron-capture%20Elements%20Cerium%20and%20Neodymium%20with%20APOGEE.pdf; Sales-Silva, JV, Cunha, K, Smith, VV, Daflon, S, Souto, D, Guerco, R, Queiroz, A, Chiappini, C, Hayes, CR, Masseron, T, Hasselquist, S, Horta, D, Prantzos, N, Zoccali, M, Allende Prieto, C, Barbuy, B, Beaton, R, Bizyaev, D, Fernandez-Trincado, JG, Frinchaboy, PM, Holtzman, JA, Johnson, JA, Joensson, H, Majewski, SR, Minniti, D, Nidever, DL, Schiavon, RP ORCID logoorcid:0000-0002-2244-0897 , Schultheis, M, Sobeck, J, Stringfellow, GS and Zasowski, G (2024) A Perspective on the Milky Way Bulge Bar as Seen from the Neutron-capture Elements Cerium and Neodymium with APOGEE. The Astrophysical Journal, 965 (2). ISSN 0004-637X |
| DOI: |
10.3847/1538-4357/ad28c2 |
| Availability: |
https://researchonline.ljmu.ac.uk/id/eprint/24616/; https://doi.org/10.3847/1538-4357/ad28c2 |
| Rights: |
cc_by |
| Accession Number: |
edsbas.7FD8ACEE |
| Database: |
BASE |