Abundances in 2 extremely metal-poor stars

DOI

It has been noted that, in classical extremely metal-poor (EMP) stars, the abundance ratio of two well-observed neutroncapture elements, Sr and Ba, is always higher than [Sr/Ba]=-0.5, which is the value of the solar r-only process; however, a handful of EMP stars have recently been found with a very low Sr/Ba ratio. We try to understand the origin of this anomaly by comparing the abundance pattern of the elements in these stars and in the classical EMP stars. For a rigorous comparison with previous data, four stars with very low Sr/Ba ratios were observed and analyzed in the same way as in the First Stars Program: analysis within LTE approximation through 1D (hydrostatic) model atmosphere, providing homogeneous abundances of nine neutron-capture elements.

Identifier
DOI http://doi.org/10.26093/cds/vizier.35710040
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/571/A40
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/571/A40
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/571/A40
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/571/A40
Provenance
Creator Spite M.; Spite F.; Bonifacio P.; Caffau E.; Francois P.; Sbordone L.
Publisher CDS
Publication Year 2014
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; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy