Extremely metal-poor giants equivalent widths

DOI

This paper reports detailed abundance analyses for four extremely metal-poor (XMP) giant stars with [Fe/H]<-3.8, based on high-resolution, high- S/N spectra from the ESO VLT (Kueyen/UVES) and LTE model atmosphere calculations. The derived [{alpha}/Fe] ratios in our sample exhibit a small dispersion, confirming previous findings in the literature, i.e. a constant overabundance of the {alpha}-elements with a very small (if any) dependence on [Fe/H]. In particular, the very small scatter we determine for [Si/Fe] suggests that this element shows a constant overabundance at very low metallicity, a conclusion which could not have been derived from the widely scattered [Si/Fe] values reported in the literature for less metal-poor stars. For the iron-peak elements, our precise abundances for the four XMP stars in our sample confirm the decreasing trend of Cr and Mn with decreasing [Fe/H], as well as the increasing trend for Co and the absence of any trend for Sc and Ni. In contrast to the significant spread of the ratios [Sr/Fe] and [Ba/Fe], we find [Sr/Ba] in our sample to be roughly solar, with a much lower dispersion than previously found for stars in the range -3.5<[Fe/H]<-2.5.

Identifier
DOI http://doi.org/10.26093/cds/vizier.34031105
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/403/1105
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/403/1105
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/403/1105
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/403/1105
Provenance
Creator Francois P.; Depagne E.; Hill V.; Spite M.; Spite F.; Plez B.,Beers T.C.; Barbuy B.; Cayrel R.; Andersen J.; Bonifacio P.; Molaro P.,Nordstroem F.; Primas B.
Publisher CDS
Publication Year 2003
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; Observational Astronomy; Physics; Stellar Astronomy