Neutron-capture elements in dwarf galaxies

DOI

The heavy elements (Z>30) are created in neutron (n)-capture processes which are predicted to happen at vastly different nucleosynthetic sites. To study these processes in an environment different from the Milky Way, we target the n-capture elements in red giant branch stars in the Sculptor dwarf spheroidal galaxy. Using ESO VLT/FLAMES spectra, we measure the chemical abundances of Y, Ba, La, Nd, and Eu, in 98 stars covering the metalliticy range -2.4<[Fe/H]~-2. We test the use of [Y/Mg] and [Ba/Mg] as chemical clocks in Sculptor. Similarly to what is observed in the Milky Way, [Y/Mg] and [Ba/Mg] increase towards younger ages. However, there is an offset in the trends, where the abundance ratios of [Y/Mg] in Sculptor are significantly lower than those of the Milky Way at any given age. This is most likely caused by metallicity dependence of yields from the s-process, as well as different relative contribution of the s-process to core-collapse supernovae in these galaxies. Comparisons of our data with that of the Milky Way and the Fornax dwarf spheroidal galaxy furthermore show that these chemical clocks are both metallicity and environment dependent.

Cone search capability for table J/A+A/631/A171/tableb1 (Atmospheric parameters and chem. abundances)

Identifier
DOI http://doi.org/10.26093/cds/vizier.36310171
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/631/A171
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/631/A171
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/631/A171
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/631/A171
Provenance
Creator Skuladottir A.; Hansen C.J; Salvadori S.; Choplin A.
Publisher CDS
Publication Year 2019
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Interdisciplinary Astronomy; Natural Sciences; Physics