J/ApJ/807/171ivo://CDS.VizieR/J/ApJ/807/171doi:10.26093/cds/vizier.18070171CDSJacobson H.R.Keller S.Frebel A.Casey A.R.Asplund M.Bessell M.S.,Da Costa G.S.Lind K.Marino A.F.Norris J.E.Pena J.M.Schmidt B.P.,Tisserand P.Walsh J.M.Yong D.Yu Q.2017-06-12T08:24:38Z2015-11-20T15:07:50ZCDS support team

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

cds-question@unistra.frchemical-abundanceschemically-peculiar-starsline-intensitiesradial-velocitysurveysThe SkyMapper Southern Sky Survey is carrying out a search for the most metal-poor stars in the Galaxy. It identifies candidates by way of its unique filter set which allows for estimation of stellar atmospheric parameters. The set includes a narrow filter centered on the CaII K 3933{AA} line, enabling a robust estimate of stellar metallicity. Promising candidates are then confirmed with spectroscopy. We present the analysis of Magellan Inamori Kyocera Echelle high-resolution spectroscopy of 122 metal-poor stars found by SkyMapper in the first two years of commissioning observations. Forty-one stars have [Fe/H]<=-3.0. Nine have [Fe/H]<=-3.5, with three at [Fe/H]~-4. A 1D LTE abundance analysis of the elements Li, C, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, Zn, Sr, Ba, and Eu shows these stars have [X/Fe] ratios typical of other halo stars. One star with low [X/Fe] values appears to be "Fe-enhanced", while another star has an extremely large [Sr/Ba] ratio: >2 Only one other star is known to have a comparable value. Seven stars are "CEMP-no" stars ([C/Fe]>0.7, [Ba/Fe]<0). 21 stars exhibit mild r-process element enhancements (0.3<=[Eu/Fe]<1.0), while four stars have [Eu/Fe]>=1.0. These results demonstrate the ability to identify extremely metal-poor stars from SkyMapper photometry, pointing to increased sample sizes and a better characterization of the metal-poor tail of the halo metallicity distribution function in the future.2015ApJ...807..171Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/807/171CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/272 : RAVE 4th data release (Kordopatis+, 2013)VII/240 : Millennium Galaxy Catalogue (Liske+, 2003)J/ApJ/798/110 : Equivalent widths of LAMOST metal-poor stars (Li+, 2015)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013)J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/MNRAS/429/126 : Atmospheric parameters from Fe lines (Ruchti+, 2013)J/ApJ/762/27 : Most metal-poor stars. III. [Fe/H]<=-3.0 stars (Yong+, 2013)J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)J/ApJ/762/25 : The most metal-poor stars in HES and SDSS. I. (Norris+, 2013)J/AJ/145/13 : Metal-poor stars from SDSS/SEGUE. I. Abundances (Aoki+, 2013)J/A+A/546/A90 : NLTE analysis of Sr lines (Bergemann+, 2012)J/ApJ/751/102 : Equivalent widths of 9 RGB in Carina dSph (Venn+, 2012)J/AJ/142/188 : Metal-poor stars from the HES using CH G-band (Placco+, 2011)J/ApJ/742/54 : CASH project II. 14 extremely metal-poor stars (Hollek+, 2011)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/ApJ/724/975 : Heavy elements abund. of metal-poor stars (Roederer+, 2010)J/ApJ/719/931 : Chemical evolution of the UMi dSph (Cohen+, 2010)J/AN/331/474 : Abundances of metal-poor stars (Frebel, 2010)J/ApJ/711/573 : Detailed abundances in a halo stellar stream (Roederer+, 2010)J/A+A/503/541 : Late-type stars neutral Li non-LTE calculations (Lind+, 2009)J/AJ/137/4377 : List of SEGUE plate pairs (Yanny+, 2009)J/ApJ/681/1524 : Detailed abundances for 28 metal-poor stars (Lai+, 2008)J/A+A/484/721 : HES survey. IV. Candidate metal-poor stars (Christlieb+, 2008)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)J/A+A/403/1105 : Extremely metal-poor giants EWs (Francois+, 2003)J/ApJS/123/639 : UBV photometry of metal-weak candidates (Norris+, 1999)J/A+A/326/751 : Chemical composition of halo and disk stars (Nissen+, 1997)J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/807/171https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/807/171http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/807/171https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/807/171https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/807/171http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/807/171GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/807/171/table1 (Observing details)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/807/171/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/807/171/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/807/171/table1?GETtext/xml+votable180.050000true0.3081667-36.56052780.0055555555555555566/16399 25021 25056 26147 26879 26888 27146 27150 27169 27237 27283 28937 28957 28998 29001 29004 29311 29482 30933 32892 32914 32921 32923 32924 32995 33019 33185 33351 33670 33673 33703 33715 33750 33753 33861 33983 34254 34495 34844 34990 34995 35008 35009 35026 35079 35122 35329 35347 35352 35367 35607 35760 35881 36098 37055 37554 38286 38510 38805 38807 38919 38929 38935 38953 38957 40445 40758 40761 40912 42307 42308 42323 42326 42878 42879 42917 43261 43365 43370 43654 43660 43741 43742 43743 43764 43941 44023 44304 44410 44460 44461 44727 44735 44776 45091 45208 45470 45591 45679 45824 45826 45935 45997 46010 46227 46230 46544 46552 46659 46940 46967 47325 47360 47610 47819 47852 47869 47943https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/807/171?format=asciiOpticaldefaultJ/ApJ/807/171/table3Equivalenth width measurements of the 122 starsIDStar identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[3387.8/6979] Wavelength0.1nmem.wldoubleSp[8/63.1] Species numeric identifier (1)phys.atmol.ionStagefloatExPot[0/5.1] Excitation potentialeVphys.atmol.excitationfloatlog(gf)[-10.4/0.7] Log oscillator strengthphys.atmol.oscStrengthfloatEW[1.3/437]? Equivalent width1e-13mspect.line.eqWidthfloatnullablef_EW[s] Flag on EW (2)meta.codecharlogX[-3.3/8.1] Log number abundancephys.abundfloatJ/ApJ/807/171/table1Observing detailsf_ID[b] b: indicates ID is a suspected binarymeta.codecharIDStar identifier (SMSS or 2MASS JHHMMSS.ss+DDMMSSs)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[0/23] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[0/85] Degree of Declination (J2000)pos.eq.dec;meta.maingmag[12.5/16.7]? The g band magnitudemagphot.mag;em.opt.Vfloatnullableg-i[0.3/1.4]? The (g-i) color indexmagphot.color;em.opt.V;em.opt.IfloatnullableDateUT date of the observationtime.epoch;obsnullableTexp[50/10140] Exposure timestime.duration;obs.exposureintSlit[0.7/1] Slit sizearcsecinstr.setupfloatRVel[-492.1/450.5] Radial velocitykm/sphys.veloc;pos.heliocentricfloatS/N45[3/82] Signal-to-noise per pixel at 4500{AA}stat.snrintS/N60[6/125] S/N per pixel at 6000 Angstromsstat.snrintJ/ApJ/807/171/table4Element abundances of the 122 starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSpSpecies identifierphys.atmol.ionStagecharIDStar identifiermeta.id;meta.maincharl_logXLimit flag on logXmeta.code.errorcharlogX[-3.3/7.5]? Log number abundancephys.abundfloatnullableNum[0/203] Number of lines usedmeta.numberintSD[0/0.5]? Standard deviationstat.stdevfloatnullablel_[X/H]Limit flag on [X/H]meta.code.error;phys.abundchar[X/H][-5.8/-0.4]? Log Species abundance relative to hydrogenphys.abund;arith.zpfloatnullablel_[X/Fe]Limit flag on [X/H]meta.code.error;phys.abundchar[X/Fe][-2.4/2]? Log Species abundance relative to ironphys.abundfloatnullableJ/ApJ/807/171/starsStellar parameters and corrected carbon abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identifiermeta.id;meta.maincharprimaryTeff[4432/5890] Effective temperatureKphys.temperature.effectiveintlog(g)L[0.5/3.4] Log LTE derived surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]L[-4/-1.3] LTE derived metallicityphys.abund.FefloatVt[1.3/3.3] Microturbulent velocitykm/sphys.velocfloatlog(g)N[0.9/3.6] Log NLTE derived surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]N[-3.8/-1.2] NLTE derived metallicityphys.abund.FefloatADisplay the 20 element abundance measured for this starmeta.ref.urlcharNobsNumber of observations for this starmeta.numberintnullableNeqNumber of EW measures for this starmeta.numberintnullablel_[C/Fe]oLimit flag on [C/Fe]ometa.code.error;phys.abundchar[C/Fe]o[-0.8/1.3]? Original log C/Fe abundancephys.abundfloatnullableCor[0/0.8]? Correction for log C/Fearith.factorfloatnullablel_[C/Fe]cLimit flag on [C/Fe]cmeta.code.error;phys.abundchar[C/Fe]c[-0.4/1.4]? Corrected log C/Fe abundancephys.abundfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar