Malmö University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Abundances of disk and bulge giants from high-resolution optical spectra IV. Zr, La, Ce, Eu
Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, 221 00 Lund, Sweden.
Malmö University, Faculty of Technology and Society (TS), Department of Materials Science and Applied Mathematics (MTM). Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, 221 00 Lund, Sweden.ORCID iD: 0000-0002-4912-8609
Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, 221 00 Lund, Sweden; Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France.
Dipartimento di Fisica, Sezione di Astronomia, Università di Trieste, via G.B. Tiepolo 11, 34131 Trieste, Italy; INAF – Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, 34131 Trieste, Italy; INFN – Sezione di Trieste, via Valerio 2, 34134 Trieste, Italy.
2019 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 631, article id A113Article in journal (Refereed) Published
Abstract [en]

Context. Observations of the Galactic bulge suggest that the disk formed through secular evolution rather than gas dissipation and/or mergers, as previously believed. This would imply very similar chemistry in the disk and bulge. Some elements, such as the alpha-elements, are well studied in the bulge, but others like the neutron-capture elements are much less well explored. Stellar mass and metallicity are factors that affect the neutron-capture process. Due to this, the enrichment of the ISM and the abundance of neutron-capture elements vary with time, making them suitable probes for Galactic chemical evolution. Aims. In this work, we make a differential comparison of neutron-capture element abundances determined in the local disk(s) and the bulge, focusing on minimising possible systematic effects in the analysis, with the aim of finding possible differences/similarities between the populations. Methods. Abundances are determined for Zr, La, Ce, and Eu in 45 bulge giants and 291 local disk giants, from high-resolution optical spectra. The abundances are determined by fitting synthetic spectra using the SME-code. The disk sample is separated into thin- and thick-disk components using a combination of abundances and kinematics. Results. We find flat Zr, La, and Ce trends in the bulge, with a similar to 0.1 dex higher La abundance compared with the disk, possibly indicating a higher s-process contribution for La in the bulge. [Eu/Fe] decreases with increasing [Fe/H], with a plateau at around [Fe/H] similar to -0.4, pointing at similar enrichment to alpha-elements in all populations. Conclusions. We find that the r-process dominated the neutron-capture production at early times both in the disks and bulge. Further, [La/Eu] ratios for the bulge are systematically higher than for the thick disk, pointing to either a) a different amount of SN II or b) a different contribution of the s-process in the two populations. Considering [(La+Ce)/Zr], the bulge and the thick disk follow each other closely, suggesting a similar ratio of high-to-low-mass asymptotic giant branch stars.

Place, publisher, year, edition, pages
EDP Sciences, 2019. Vol. 631, article id A113
Keywords [en]
stars: abundances, Galaxy: bulge, solar neighborhood, Galaxy: evolution
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
URN: urn:nbn:se:mau:diva-18679DOI: 10.1051/0004-6361/201936343ISI: 000507288200002Scopus ID: 2-s2.0-85082694785OAI: oai:DiVA.org:mau-18679DiVA, id: diva2:1477046
Available from: 2020-10-16 Created: 2020-10-16 Last updated: 2024-01-22Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records

Jönsson, Henrik

Search in DiVA

By author/editor
Jönsson, Henrik
By organisation
Department of Materials Science and Applied Mathematics (MTM)
In the same journal
Astronomy and Astrophysics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 27 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf