First Stars. III. A detailed elemental abundance study of four extremely metal-poor giant stars
(2003) In Astronomy & Astrophysics 403(3). p.1105-1114- Abstract
- This paper reports detailed abundance analyses for four extremelymetal-poor (XMP) giant stars with [Fe/H]<-3.8, based onhigh-resolution, high-S/N spectra from the ESO VLT (Kueyen/UVES) and LTEmodel atmosphere calculations. The derived [alpha /Fe] ratios in oursample exhibit a small dispersion, confirming previous findings in theliterature, i.e. a constant overabundance of the alpha -elements with avery small (if any) dependence on [Fe/H]. In particular, the very smallscatter we determine for [Si/Fe] suggests that this element shows aconstant overabundance at very low metallicity, a conclusion which couldnot have been derived from the widely scattered [Si/Fe] values reportedin the literature for less metal-poor stars. For the iron-peak... (More)
- This paper reports detailed abundance analyses for four extremelymetal-poor (XMP) giant stars with [Fe/H]<-3.8, based onhigh-resolution, high-S/N spectra from the ESO VLT (Kueyen/UVES) and LTEmodel atmosphere calculations. The derived [alpha /Fe] ratios in oursample exhibit a small dispersion, confirming previous findings in theliterature, i.e. a constant overabundance of the alpha -elements with avery small (if any) dependence on [Fe/H]. In particular, the very smallscatter we determine for [Si/Fe] suggests that this element shows aconstant overabundance at very low metallicity, a conclusion which couldnot have been derived from the widely scattered [Si/Fe] values reportedin the literature for less metal-poor stars. For the iron-peak elements,our precise abundances for the four XMP stars in our sample confirm thedecreasing trend of Cr and Mn with decreasing [Fe/H], as well as theincreasing trend for Co and the absence of any trend for Sc and Ni. Incontrast to the significant spread of the ratios [Sr/Fe] and [Ba/Fe], wefind [Sr/Ba] in our sample to be roughly solar, with a much lowerdispersion than previously found for stars in the range -3.5 < [Fe/H]< -2.5.Based on observations made with the ESO Very Large Telescope at ParanalObservatory, Chile (Large Programme ID 165.N-0276(A)).The complete version of Table 5 is only available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp:/ /cdsweb.u-strasbg.fr/cgi-bin/qcat?J /A+A/403/1105 (Less)
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https://lup.lub.lu.se/record/130528
- author
- organization
- publishing date
- 2003
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- stars: abundances, stars: Population II, Galaxy: abundances, Galaxy: halo, nuclear reactions, nucleosynthesis, abundances
- in
- Astronomy & Astrophysics
- volume
- 403
- issue
- 3
- pages
- 1105 - 1114
- publisher
- EDP Sciences
- external identifiers
-
- wos:000183080400034
- scopus:0037732843
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361:20030438
- language
- English
- LU publication?
- yes
- id
- ef9985cc-0925-4d2d-bb02-a40f3aa77b23 (old id 130528)
- date added to LUP
- 2016-04-01 16:41:50
- date last changed
- 2022-12-12 20:39:27
@article{ef9985cc-0925-4d2d-bb02-a40f3aa77b23, abstract = {{This paper reports detailed abundance analyses for four extremelymetal-poor (XMP) giant stars with [Fe/H]<-3.8, based onhigh-resolution, high-S/N spectra from the ESO VLT (Kueyen/UVES) and LTEmodel atmosphere calculations. The derived [alpha /Fe] ratios in oursample exhibit a small dispersion, confirming previous findings in theliterature, i.e. a constant overabundance of the alpha -elements with avery small (if any) dependence on [Fe/H]. In particular, the very smallscatter we determine for [Si/Fe] suggests that this element shows aconstant overabundance at very low metallicity, a conclusion which couldnot have been derived from the widely scattered [Si/Fe] values reportedin the literature for less metal-poor stars. For the iron-peak elements,our precise abundances for the four XMP stars in our sample confirm thedecreasing trend of Cr and Mn with decreasing [Fe/H], as well as theincreasing trend for Co and the absence of any trend for Sc and Ni. Incontrast to the significant spread of the ratios [Sr/Fe] and [Ba/Fe], wefind [Sr/Ba] in our sample to be roughly solar, with a much lowerdispersion than previously found for stars in the range -3.5 < [Fe/H]< -2.5.Based on observations made with the ESO Very Large Telescope at ParanalObservatory, Chile (Large Programme ID 165.N-0276(A)).The complete version of Table 5 is only available in electronic form atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp:/ /cdsweb.u-strasbg.fr/cgi-bin/qcat?J /A+A/403/1105}}, author = {{François, P. and Depagne, E. and Hill, V. and Spite, M. and Spite, F. and Plez, B. and Beers, T. C. and Barbuy, B. and Cayrel, R. and Andersen, J. and Bonifacio, P. and Molaro, P. and Nordström, Birgitta and Primas, F.}}, issn = {{0004-6361}}, keywords = {{stars: abundances; stars: Population II; Galaxy: abundances; Galaxy: halo; nuclear reactions; nucleosynthesis; abundances}}, language = {{eng}}, number = {{3}}, pages = {{1105--1114}}, publisher = {{EDP Sciences}}, series = {{Astronomy & Astrophysics}}, title = {{First Stars. III. A detailed elemental abundance study of four extremely metal-poor giant stars}}, url = {{https://lup.lub.lu.se/search/files/4753438/624155.pdf}}, doi = {{10.1051/0004-6361:20030438}}, volume = {{403}}, year = {{2003}}, }