J/A+A/693/A211ivo://CDS.VizieR/J/A+A/693/A211doi:10.26093/cds/vizier.36930211CDSGuo Y.Storm N.Bergemann M.Lian J.Alexeeva S.Li Y.Ezzeddine R.,Jeffrey G.Chen X.2025-03-03T20:01:19Z2025-01-17T08:52:49ZCDS support team

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

cds-question@unistra.frchemically-peculiar-starschemical-abundancesAs a key to chemical evolutionary studies, the distribution of elements in galactic provides a wealth of information to understand the individual star formation histories of galaxies. The r-process is a complex nucleosynthesis process, and the origin of r-process elements is heavily debated. Europium (Eu) is viewed as an almost pure r-process element. Accurate measurements of europium abundances in cool stars are essential for an enhanced understanding of the r-process mechanisms. We measure the abundance of Eu in solar spectra and a sample of metal-poor stars in the Galactic halo and metal-poor disk, with the metallicities ranging from -2.4 to -0.5dex, using non-local thermodynamic equilibrium (NLTE) line formation. We compare these measurements with Galactic Chemical Evolution (GCE) models to explore the impact of the NLTE corrections on the contribution of r-process site in Galactic chemical evolution. In this work, we used NLTE line formation, as well as one-dimensional (1D) hydrostatic and spatial averages of three-dimensional hydrodynamical (<3D>) model atmospheres to measure the abundance of Eu based on both the EuII 4129{AA} and EuII 6645{AA} lines for solar spectra and metal-poor stars. We find that for EuII 4129{AA} line the NLTE modeling leads to higher (0.04dex) solar Eu abundance in 1D and higher (0.07dex) in <3D> NLTE while NLTE modeling leads to higher (0.01dex) solar Eu abundance in 1D and lower (0.03dex) in <3D> NLTE for EuII 6645{AA} line. Although the NLTE corrections for the EuII {lambda} 4129{AA} and EuII {lambda} 6645{AA} lines are opposite, the discrepancy between the abundances derived from these individual lines reduces after applying NLTE corrections, highlighting the critical role of NLTE abundance determinations. By comparing these measurements with Galactic chemical evolution (GCE) models, we find that the amount of NLTE correction does not require significant change of the parameters for Eu production in GCE models.2025A&A...693A.211Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/693/A211CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/557/A26 : STAGGER-grid of 3D stellar models. I. (Magic+, 2013)J/A+A/560/A8 : STAGGER-grid of 3D stellar models. II. (Magic+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/693/A211https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/693/A211http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/693/A211https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/693/A211https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/693/A211http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/693/A211GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/693/A211/table3 (Results of Eu abundance based on EuII 4129{AA} line)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A211/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A211/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A211/table3?GETtext/xml+votable180.050000true48.8992847-9.79549860.005555555555555556Cone search capability for table J/A+A/693/A211/table4 (Results of Eu abundance based on EuII 6645{AA} line)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A211/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A211/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A211/table4?GETtext/xml+votable180.050000true11.8894753-45.16180780.0055555555555555566/16929 17033 17127 17134 17698 18606 20527 20538 20635 20882 21202 21228-21229 21241 24602 24618 24644 24663 24668 24887 24994 25061 25158 25207 25350 25394 25400 25405 25520 25624 25635 25696 25767 25786 25857 25938 25990 26168 26241 26720 26722 26725 26767 26827 27016 30761 30923 31117 33030 33121 33142 33523 34141 34260 34276 34427 34478 34493 34588 34610 34908 34935 35084 35288 35359 35857 36002 36105 36172 36467 36486 36710 36783 37543 37551 38336 38683 38772 38775 38779-38780 38851 39084 39188 39443 39490 39817 39847 40133 40278 40337 40498 40911 43307 43487 43577 43629 43663 43862 43905 43976 43992 44002 44006 44260 44458 44478 44641 44701 44754 44780 44830 44841 44847 44851 44901 44923 44960 45019 45037 45216 45622 45748 45764 45786 45804 45857 45954 46324 46418 46666 46696 46942 47223 47373 47379 47564 47589 47711 47940 47954 47967 48087 48163 48246 48256 48272 48358 48436 48588 48641 48648 48672 48677 48694 48749-48750 48752 48861 49093 49103 49124https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/693/A211?format=asciidefaultJ/A+A/693/A211/table3Results of Eu abundance based on EuII 4129{AA} linerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar identifier in the RAVE catalog or Tychometa.id;meta.maincharTeffEffective temperature of the starKphys.temperature.effectiveintloggSurface gravity of the starlog(cm.s**-2)phot.sbfloat[Fe/H]Metallicity ([Fe/H]) of the starphys.abund.ZfloatvmicMicroturbulence velocitykm/sphys.veloc.microTurbfloatLTELTE abundancephys.abundfloatNLTENLTE abundancephys.abundfloatflagCMEP[*] * indicates carbon-enhanced metal-poor stars with s-process element enhancementmeta.code.errorcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/693/A211/table4Results of Eu abundance based on EuII 6645{AA} lineSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar identifier in the RAVE catalog or Tychometa.id;meta.maincharTeffEffective temperature of the starKphys.temperature.effectiveintloggSurface gravity of the starlog(cm.s**-2)phot.sbfloat[Fe/H]Metallicity ([Fe/H]) of the starphys.abund.ZfloatvmicMicroturbulence velocitykm/sphys.veloc.microTurbfloatLTELTE abundancephys.abundfloatNLTENLTE abundancephys.abundfloatflagCMEP[*] * indicates carbon-enhanced metal-poor stars with s-process element enhancementmeta.code.errorchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main