J/AJ/145/107ivo://CDS.VizieR/J/AJ/145/107doi:10.26093/cds/vizier.51450107CDSJacobson H.R.Friel E.D.2017-07-10T06:21:49Z2014-05-07T14:42:49ZCDS support team

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

cds-question@unistra.fropen-star-clustersgiant-starschemical-abundancesWe present an analysis of the s-process elements Zr, Ba, and La and the r-process element Eu in a sample of 50 stars in 19 open clusters. Stellar abundances of each element are based on measures of a minimum of two lines per species via both equivalent width and spectrum synthesis techniques. We investigate cluster mean neutron-capture abundance trends as a function of cluster age and location in the Milky Way disk and compare them to results found in other studies in the literature. We find a statistically significant trend of increasing cluster [Ba/Fe] as a function of decreasing cluster age, in agreement with recent findings for other open cluster samples, supporting the increased importance of low-mass asymptotic giant branch stars to the generation of s-process elements. However, the other s-process elements, [La/Fe] and [Zr/Fe], do not show similar dependences, in contrast to theoretical expectations and the limited observational data from other studies. Conversely, cluster [Eu/Fe] ratios show a slight increase with increasing cluster age, although with marginal statistical significance. Ratios of [s/r]-process abundances, [Ba/Eu] and [La/Eu], however, show more clearly the increasing efficiency of s-process relative to r-process enrichment in open cluster chemical evolution, with significant increases among younger clusters. Last, cluster neutron-capture element abundances appear to be independent of Galactocentric distance. We conclude that a homogeneous analysis of a larger sample of open clusters is needed to resolve the apparent discrepant conclusions between different studies regarding s-process element abundance trends with age to better inform models of galactic chemical evolution.2013AJ....145..107Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/145/107CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/419/1350 : Red giants abundances in 4 open clusters (Reddy+, 2012)J/AJ/144/95 : Stars abundance in the outer galactic disk. IV. (Yong+, 2012)J/AJ/142/59 : Chemical abundance in 10 open clusters (Jacobson+, 2011)J/A+A/535/A30 : Chemical abundance of stars in open clusters (Carrera+, 2011)J/A+A/360/499 : Equivalent widths of 9 stars of M 67 (Tautvaisiene+, 2000)J/A+A/511/A56 : Abundances of five open clusters (Pancino+, 2010)J/AJ/139/1942 : EWs of red giants in 6 open clusters (Friel+, 2010)J/AJ/137/4753 : Red giants EWs in 4 open clusters (Jacobson+, 2009)J/AJ/134/1216 : Abundances of NGC 7142, 6939, IC 4756 stars (Jacobson+, 2007)J/AJ/129/2725 : Equivalent widths of red giants in Berkeley 17 (Friel+, 2005)J/A+A/360/499 : Equivalent widths of 9 stars of M 67 (Tautvaisiene+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/145/107https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/145/107http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/145/107https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/145/107https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/145/107http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/145/107GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/145/107/clusters (Cluster sample , and their mean abundances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/145/107/clusters?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/145/107/clusters?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/145/107/clusters?GETtext/xml+votable180.050000true80.15630.590.005555555555555556Cone search capability for table J/AJ/145/107/stars (Stellar atmospheric parameters and Fe abundances , individual [X/Fe] rations for Zr , Ba , La , and Eu)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/145/107/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/145/107/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/145/107/stars?GETtext/xml+votable180.050000true80.198958330.5280.0055555555555555566/1481 1486 3076 3091 4078 4298 14303 15594 15595 15759 21719 22239 22499 23612 23745 23761 24121 24330 24344 24491https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/145/107?format=asciiOpticaldefaultJ/AJ/145/107/clustersCluster sample , and their mean abundancesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster namemeta.id;meta.maincharprimaryAgeCluster age (adopted from Salaris et al., 2004A&A...414..163S) (1)Gyrtime.agefloatf_Age[d] Cluster age from Villanova et al. 2007 (1)meta.codecharDistDistancekpcpos.distance;pos.heliocentricfloatRgcGalactocentric distance (R_{Sun}_=8.5kpc)kpcpos.distance;pos.galactocentricfloatRefReference for distances (2)meta.ref;pos.framecharN1Number of starsmeta.numberintN2? Number of stars (from spectra obtained on Keck)meta.numberintnullableTelTelescope (KPNO4m, Keck, or HET) (3)meta.id;instr.telcharC[ab] Calculation of [X/Fe] ratios (4)meta.codechar[Fe/H]Cluster mean [Fe/H] abundancelog(Sun)phys.abund.Fe;stat.meanfloats_[Fe/H]1{sigma} standard deviation in [Fe/H]log(Sun)stat.stdev;phys.abund.Fefloat[Zr/H]Cluster mean [Zr/H] abundancelog(Sun)phys.abundfloats_[Zr/H]1{sigma} standard deviation in [Zr/H]log(Sun)stat.stdev;phys.abundfloat[Ba/Fe]Cluster mean [Ba/Fe] abundancelog(Sun)phys.abundfloats_[Ba/Fe]1{sigma} standard deviation in [Ba/Fe]log(Sun)stat.stdev;phys.abundfloat[La/Fe]Cluster mean [La/Fe] abundancelog(Sun)phys.abundfloats_[La/Fe]1{sigma} standard deviation in [La/Fe]log(Sun)stat.stdev;phys.abundfloat[Eu/Fe]? Cluster mean [Eu/Fe] abundancelog(Sun)phys.abundfloatnullables_[Eu/Fe]? 1{sigma} standard deviation in [Eu/Fe]log(Sun)stat.stdev;phys.abundfloatnullableNNumber of stars used to determined the mean abundances (5)meta.numberintF+10Display the data from Friel et al. (2010, cat. J/AJ/139/1942) if anymeta.numberintnullable_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.mainnullable_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainnullableJ/AJ/145/107/table3Line listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement/Ion (Zr I, Ba II, La II, or Eu II)meta.notecharlambdaWavelength ({AA})0.1nmem.wlfloatEPExcitation potentialeVphys.atmol.excitationfloatloggfLog of the oscillator strengthphys.atmol.oscStrengthfloatf_loggf[e] Origin of loggf (2)meta.codecharAbund1Element Solar abundance (log{epsilon}(Fe)) (3)phys.abundfloatAbund2Element Solar abundance (log{epsilon}(Fe)) (4)phys.abundfloatAbund3Element Arcturus abundance (log{epsilon}(X)) (5)phys.abundfloatf_Abund3[f] This abundance is forced to match that for the EuII 6645 feature; details in Section 3.2.4meta.codechar[X/Fe]Arcturus [X/Fe] ratio (6)log(Sun)phys.abundfloatJ/AJ/145/107/starsStellar atmospheric parameters and Fe abundances , individual [X/Fe] rations for Zr , Ba , La , and EuSimbadNameSimbad column added by the CDSmeta.idchar[Zr/Fe]3Abundance from the ZrI{lambda}6143 lines (7)log(Sun)phys.abundfloat<[Zr/Fe]>Mean star [Zr/Fe] abundancelog(Sun)phys.abundfloats_<[Zr/Fe]>1{sigma} standard deviation in <[Zr/Fe]>log(Sun)stat.stdev;phys.abundfloat[Ba/Fe]1Abundance from the BaII{lambda}5853 lines (8)log(Sun)phys.abundfloat[Ba/Fe]2Abundance from the BaII{lambda}6141 lines (8)log(Sun)phys.abundfloat[Ba/Fe]3Abundance from the BaII{lambda}6496 lines (8)log(Sun)phys.abundfloat<[Ba/Fe]>Mean star [Ba/Fe] abundance (9)log(Sun)phys.abundfloats_<[Ba/Fe]>1{sigma} standard deviation in <[Ba/Fe]> (9)log(Sun)stat.stdev;phys.abundfloat[La/Fe]1? Abundance from LaII{lambda}6262 lines (10)log(Sun)phys.abundfloatnullablee_[La/Fe]1? Uncertainty in [La/Fe]1 (11)log(Sun)stat.error;phys.abundfloatnullable[La/Fe]2? Abundance from LaII{lambda}6390 lines (10)log(Sun)phys.abundfloatnullablee_[La/Fe]2? Uncertainty in [La/Fe]2 (11)log(Sun)stat.error;phys.abundfloatnullable<[La/Fe]>? Mean star [La/Fe] abundancelog(Sun)phys.abundfloatnullables_<[La/Fe]>? 1{sigma} standard deviation in <[La/Fe]>log(Sun)stat.stdev;phys.abundfloatnullable[Eu/Fe]1? Abundance from EuII{lambda}6437 lines (12)log(Sun)phys.abundfloatnullablee_[Eu/Fe]1? Uncertainty in [Eu/Fe]1 (13)log(Sun)stat.error;phys.abundfloatnullable[Eu/Fe]2? Abundance from EuII{lambda}6645 lines (12)log(Sun)phys.abundfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster namemeta.id.parentcharStarStar name (in Cluster)meta.id;meta.maincharTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloatvtMicroturbulent velocitykm/sphys.velocfloat[FeI/H]Metallicity from FeI lines (1)log(Sun)phys.abund.Zfloats_[FeI/H]1{sigma} standard deviation in [FeI/H]log(Sun)stat.stdev;phys.abundfloato_[FeI/H]Number of FeI linesmeta.numberint[FeII/H]Metallicity from FeII lines (1)log(Sun)phys.abund.Zfloats_[FeII/H]1{sigma} standard deviation in [FeII/H]log(Sun)stat.stdev;phys.abundfloato_[FeII/H]Number of FeII linesmeta.numberint[Zr/Fe]1Abundance from the ZrI{lambda}6127 lines (7)log(Sun)phys.abundfloat[Zr/Fe]2? Abundance from ZrI{lambda}6134 lines (7)log(Sun)phys.abundfloatnullablee_[Eu/Fe]2? Uncertainty in [Eu/Fe]2 (13)log(Sun)stat.error;phys.abundfloatnullable<[Eu/Fe]>? Mean star [Eu/Fe] abundancelog(Sun)phys.abundfloatnullables_<[Eu/Fe]>? 1{sigma} standard deviation in <[Eu/Fe]>log(Sun)stat.stdev;phys.abundfloatnullableOCatCross-match with Yong et al. (2012, cat. J/AJ/144/95), Jacobson et al. (2009, cat. J/AJ/137/4753), and Friel et al. (2010, cat. J/AJ/139/1942) within 1.5"meta.ref.urlintnullable_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.mainnullable_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainnullable