J/ApJ/802/93ivo://CDS.VizieR/J/ApJ/802/93doi:10.26093/cds/vizier.18020093CDSSimon J.D.Jacobson H.R.Frebel A.Thompson I.B.Adams J.J.,Shectman S.A.2017-10-11T05:13:11Z2015-09-02T09:40:42ZCDS support team

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

cds-question@unistra.frchemical-abundancesline-intensitieschemically-peculiar-starsWe present a homogeneous chemical abundance analysis of five of the most metal-poor stars in the Sculptor dwarf spheroidal galaxy. We analyze new and archival high resolution spectroscopy from Magellan/MIKE and VLT/UVES and determine stellar parameters and abundances in a consistent way for each star. Two of the stars in our sample, at [Fe/H]=-3.5 and [Fe/H]=-3.8, are new discoveries from our Ca K survey of Sculptor, while the other three were known in the literature. We confirm that Scl 07-50 is the lowest metallicity star identified in an external galaxy, at [Fe/H]=-4.1. The two most metal-poor stars both have very unusual abundance patterns, with striking deficiencies of the {alpha} elements, while the other three stars resemble typical extremely metal-poor Milky Way halo stars. We show that the star-to-star scatter for several elements in Sculptor is larger than that for halo stars in the same metallicity range. This scatter and the uncommon abundance patterns of the lowest metallicity stars indicate that the oldest surviving Sculptor stars were enriched by a small number of earlier supernovae, perhaps weighted toward high-mass progenitors from the first generation of stars the galaxy formed.2015ApJ...802...93Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/802/93CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/574/A129 : The First CEMP star in the Sculptor dSph (Skuladottir+, 2015)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/A+A/562/A146 : Chemical abundances of 8 metal-poor stars (Ishigaki+, 2014)J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/A+A/541/A143 : NLTE Corrections of the Ca lines (Spite+, 2012)J/MNRAS/414/3492 : JHKs photometry of Sculptor dSph galaxy (Menzies+, 2011)J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)J/AJ/137/3100 : Radial velocities of 4 dSph galaxies (Walker+, 2009)J/ApJ/705/328 : Abundance measurements in Sculptor dSph (Kirby+, 2009)J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)J/AJ/131/375 : Phot. & vel. of Sculptor dSph giants (Westfall+, 2006)J/AJ/130/1065 : Members of the Sculptor dSph galaxy (Coleman+, 2005)J/A+AS/142/467 : Broadening of metallic lines by H collisions (Barklem+ 2000)J/AJ/110/2747 : Stars in Sculptor dwarf spheroidal galaxy (Schweitzer+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/802/93https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/802/93http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/802/93https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/802/93https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/802/93http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/802/93GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/802/93/table1 (Coordinates and stellar parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/802/93/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/802/93/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/802/93/table1?GETtext/xml+votable180.050000true14.9114583-33.77072220.0055555555555555566/35549 357203.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/802/93?format=asciiOpticaldefaultJ/ApJ/802/93/table1Coordinates and stellar parametersSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharprimaryRAJ2000[0/1] Hour of Right Ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000[33/34] Degree of Declination (J2000) (1)pos.eq.dec;meta.mainVmag[18.3/19.2] V-band magnitude (1)magphot.mag;em.opt.VfloatV-IV-I color index (1)magphot.color;em.opt.V;em.opt.IfloatV-KsV-Ks color index (1)(2)magphot.color;em.opt.V;em.IR.KfloatTeff[4495/4945] Derived stellar effective temperatureKphys.temperature.effectiveinte_Teff[150] Uncertainty in TeffKstat.error;phys.temperature.effectiveintlog(g)[0.8/2] Log derived stellar surface gravitylog(cm.s**-2)phys.gravityfloate_log(g)[0.3] Uncertainty in log(g)log(cm.s**-2)stat.errorfloatVt[1.8/2.7] Microturbulence velocitykm/sphys.veloc.microTurbfloate_Vt[0.3] Uncertainty in Vtkm/sstat.errorfloat[Fe/H][-4.1/-3.3] Iron to hydrogen abundance ratio relative to the Sunlog(Sun)phys.abund.Fe;arith.ratiofloatS/N[76/204] 535nm signal to noise ratio (3)stat.snrintOCatDisplay data from Menzies et al. 2011, J/MNRAS/414/3492, Walker et al. 2009, J/AJ/137/3100, within 1"meta.ref.urlintnullableAbDisplay the equivalent widths and abundances for this starmeta.ref.urlcharJ/ApJ/802/93/table2Equivalent widthsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharIonSpecies identifierphys.atmol.ionStagecharlambda[3727.6/6767.8] Wavelength in Angstroms0.1nmem.wlfloatExPot[0/4.4]? Excitation Potential {chi}eVphys.atmol.excitationfloatnullablelog(gf)[-5/0.7]? Log of the oscillator strengthphys.atmol.oscStrengthfloatnullableEW[8/196]? Equivalent width (m{AA})1e-13mspect.line.eqWidthfloatnullablef_log(A)[s] Abundance derived from sythetic spectrummeta.codecharl_log(A)Limit flag on log(A)meta.code.errorcharlog(A)[-3.4/5.5]? Log number abundance log{epsilon}meta.idfloatnullableCmpCompare the equivalent widths and abundances for linemeta.ref.urlchar