J/A+A/693/A293ivo://CDS.VizieR/J/A+A/693/A293doi:10.26093/cds/vizier.36930293CDSLombardo L.Hansen C.J.Rizzuti F.Cescutti G.Mashonkina L.I.,Francois P.Bonifacio P.Caffau E.Alencastro Puls A.,Fernandes de Melo R.Gallagher A.J.Skuladottir A.Koch Hansen A.J.,Sbordone L.2025-03-03T20:01:33Z2025-01-24T09:51:28ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgiant-starschemical-abundancesvisible-astronomyThe chemical abundances of elements such as barium and the lanthanides are essential to understand the nucleosynthesis of heavy elements in the early Universe as well as the contribution of different neutron capture processes (e.g. slow versus rapid) at different epochs. The Chemical Evolution of R-process Elements in Stars (CERES) project aims to provide a homogeneous analysis of a sample of metal-poor stars ([Fe/H]<-1.5) to improve our understanding of the nucleosynthesis of neutron capture elements, in particular the r-process elements, in the early Galaxy. Our data consist of a sample of high resolution and high signal-to-noise ratio UVES spectra. The chemical abundances were derived through spectrum synthesis, using the same model atmospheres and stellar parameters as derived in the first paper of the CERES series. We measured chemical abundances or upper limits of seven heavy neutron capture elements (Ba, La, Ce, Pr, Nd, Sm, and Eu) for a sample of 52 metal-poor giant stars. We estimated through the mean shift clustering algorithm that at [Ba/H]=-2.4 and [Fe/H]=-2.4 a variation in the trend of [X/Ba], with X=La,Nd,Sm,Eu, versus [Ba/H] occurs. This result suggests that, for [Ba/H]<-2.4, Ba nucleosynthesis in the Milky Way halo is primarily due to the r-process, while for [Ba/H]>-2.4 the effect of the s-process contribution begins to be visible. In our sample, stars with [Ba/Eu] compatible with Solar system pure r-process value (hereafter, r-pure) do not show any particular trend compared to other stars, suggesting r-pure stars may form in similar environments to stars with less pure r-process enrichments. Homogeneous investigations of high resolution and signal-to-noise ratio spectra are crucial for studying the heavy elements formation, as they provide abundances that can be used to test nucleosynthesis models as well as Galactic chemical evolution models.2025A&A...693A.293Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/693/A293CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/665/A10 : CERES I. Abundances for 52 star (Lombardo+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/693/A293https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/693/A293http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/693/A293https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/693/A293https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/693/A293http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/693/A293GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/693/A293/stars (stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A293/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A293/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A293/stars?GETtext/xml+votable180.050000true7.8204583-16.79466670.0055555555555555566/51 16569 16821 16893 17578 17642 21087 21089 21719 22564 22576 22600 23428 24858 25639 26242 26347 26457 27763 27767 28054 31427 31451 31757 32468 33470-33471 34246 34593 34595 35395 35551 36135 36365 36407 36788 37109 37144 37290 37644 41118 44208 44575 44771 45694 45797 45825 46155 46490 46506 46512 46902https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/693/A293?format=asciiOpticaldefaultJ/A+A/693/A293/starsstarsStarStellar name (CESHHMM+DDMM)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharPapIDisplay the Paper I (Cat. J/A+A/665/A10) datameta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.idcharJ/A+A/693/A293/table1Chemical abundances with uncertainties for our starso_BaNumber of BaII lines usedmeta.numberint[Eu/Fe]EuII over FeII abundance ratiophys.abundfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStellar name (CESHHMM+DDMM)meta.id;meta.mainchar[FeII/H]FeII abundance relative to the Sunphys.abundfloatA(Ba)? Ba abundance from BaII linesphys.abundfloatnullablesigma(Ba)? Line-to-line scatter for BaII linesstat.stdevfloatnullable[Ba/H]? Ba abundance relative to the Sunphys.abundfloatnullable[Ba/Fe]? BaII over FeII abundance ratiophys.abundfloatnullableo_LaNumber of LaII lines usedmeta.numberintl_A(La)Upper limit flag on La abundancemeta.code.errorcharA(La)? La abundance from LaII linesphys.abundfloatnullablesigma(La)? Line-to-line scatter for LaII linesstat.stdevfloatnullable[La/H]? La abundance relative to the Sunphys.abundfloatnullable[La/Fe]? LaII over FeII abundance ratiophys.abundfloatnullableo_CeNumber of CeII lines usedmeta.numberintl_A(Ce)Upper limit flag on Ce abundancemeta.code.errorcharA(Ce)? Ce abundance from CeII linesphys.abundfloatnullablesigma(Ce)? Line-to-line scatter for CeII linesstat.stdevfloatnullable[Ce/H]? Ce abundance relative to the Sunphys.abundfloatnullable[Ce/Fe]? CeII over FeII abundance ratiophys.abundfloatnullableo_PrNumber of PrII lines usedmeta.numberintl_A(Pr)Upper limit flag on Pr abundancemeta.code.errorcharA(Pr)? Pr abundance from PrII linesphys.abundfloatnullablesigma(Pr)? Line-to-line scatter for PrII linesstat.stdevfloatnullable[Pr/H]? Pr abundance relative to the Sunphys.abundfloatnullable[Pr/Fe]? PrII over FeII abundance ratiophys.abundfloatnullableo_NdNumber of NdII lines usedmeta.numberintl_A(Nd)Upper limit flag on Nd abundancemeta.code.errorcharA(Nd)Nd abundance from NdII linesphys.abundfloatsigma(Nd)? Line-to-line scatter for NdII linesstat.stdevfloatnullable[Nd/H]Nd abundance relative to the Sunphys.abundfloat[Nd/Fe]NdII over FeII abundance ratiophys.abundfloato_SmNumber of SmII lines usedmeta.numberintl_A(Sm)Upper limit flag on Sm abundancemeta.code.errorcharA(Sm)? Sm abundance from SmII linesphys.abundfloatnullablesigma(Sm)? Line-to-line scatter for SmII linesstat.stdevfloatnullable[Sm/H]? Sm abundance relative to the Sunphys.abundfloatnullable[Sm/Fe]? SmII over FeII abundance ratiophys.abundfloatnullableo_EuNumber of EuII lines usedmeta.numberintl_A(Eu)Upper limit flag on Eu abundancemeta.code.errorcharA(Eu)Eu abundance from EuII linesphys.abundfloatsigma(Eu)? Line-to-line scatter for EuII linesstat.stdevfloatnullable[Eu/H]Eu abundance relative to the Sunphys.abundfloat