J/ApJ/719/931ivo://CDS.VizieR/J/ApJ/719/931doi:10.26093/cds/vizier.17190931CDSCohen J.G.Huang W.2017-06-12T08:25:22Z2012-08-22T09:08:56ZCDS support team

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

cds-question@unistra.frline-intensitiesgiant-starseffective-temperatureWe present an abundance analysis based on high-resolution spectra of 10 stars selected to span the full range in metallicity in the Ursa Minor (UMi) dwarf spheroidal (dSph) galaxy. We find that [Fe/H] for the sample stars ranges from -1.35 to -3.10 dex. Combining our sample with previously published work for a total of 16 luminous UMi giants, we establish the trends of abundance ratios [X/Fe] as functions of [Fe/H] for 15 elements. In key cases, particularly for the {alpha}-elements, these trends resemble those for stars in the outer part of the Galactic halo, especially at the lowest metallicities probed. The neutron-capture elements show an r-process distribution over the full range of Fe metallicity reached in this dSph galaxy. This suggests that the duration of star formation in the UMi dSph was shorter than in other dSph galaxies. The derived ages for a larger sample of UMi stars with more uncertain metallicities also suggest a population dominated by uniformly old (~13Gyr) stars, with a hint of an age-metallicity relationship. We note the presence of two UMi giants with [Fe/H]<-3.0 dex in our sample and reaffirm that the inner Galactic halo could have been formed by early accretion of Galactic satellite galaxies and dissolution of young globular clusters, while the outer halo could have formed from those satellite galaxies that accreted somewhat later.2010ApJ...719..931Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/719/931CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/701/1053 : Abundances of 8 stars in the Draco dSph (Cohen+, 2009)J/ApJ/617/L41 : Red giant variable candidates in UMi dSph (Mighell+, 2004)J/AJ/125/1352 : Ursa Minor dSph M,T2, DDO51 photometry (Palma+, 2003)J/AJ/124/3222 : VI photometry of Draco and UMi galaxies (Bellazzini+, 2002)J/AJ/110/2131 : M/L for Draco and UMi. I. (Armandroff+ 1995)J/AJ/90/2221 : UMi dwarf galaxy BV photometry (Olszewski+, 1985)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/719/931https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/719/931http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/719/931https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/719/931https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/719/931http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/719/931GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/719/931/stars (Stellar parameters for the Ursa Minor giants sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/719/931/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/719/931/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/719/931/stars?GETtext/xml+votable180.050000true227.020708367.23355560.0055555555555555566/11691https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/719/931?format=asciiOpticaldefaultJ/ApJ/719/931/starsStellar parameters for the Ursa Minor giants sampleSimbadNameSimbad column added by the CDSmeta.idcharS/NSignal to noise ratio (2)stat.snrintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar designation (1)meta.id;meta.maincharprimaryRAJ2000Hour of right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000) (1)pos.eq.dec;meta.mainVmagV-band magnitude (1)magphot.mag;em.opt.VfloatImagI-band magnitude (1)magphot.mag;em.opt.IfloatObsYear of observationtime.epochnullableExpExposure timestime.duration;obs.exposureintP03Cross-match with Palma et al., 2003, Cat. J/AJ/125/1352, within 1.5"meta.ref.urlintnullableTeffpPhotometric effective temperatureKphys.temperature.effectiveintloggpPhotometric surface gravitylog(cm.s**-2)phys.gravityfloatTeffsSpectroscopic effective temperatureKphys.temperature.effectiveintloggsSpectroscopic surface gravitylog(cm.s**-2)phys.gravityfloatVtTurbulent velocitykm/sphys.veloc.microTurbfloatRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatJ/ApJ/719/931/ewEquivalent widths for ten stars in the Ursa Minor dSphrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar designationmeta.id;meta.maincharlambdaWavelength ({AA})0.1nmem.wlfloatf_lambda[ab] dubious or discrepant line (1)meta.codecharIonIon identificationphys.atmol.ionStagecharchiExcitation potentialeVphys.atmol.excitationfloatlog(gf)Log of the oscillator strengthphys.atmol.oscStrengthfloatl_EW[<=] Limit flag on EWmeta.code.error;spect.line.eqWidthcharEW? Equivalent width (m{AA})1e-13mspect.line.eqWidthfloatnullable