J/MNRAS/485/5153ivo://CDS.VizieR/J/MNRAS/485/5153doi:10.26093/cds/vizier.74855153CDSMarino A.F.Da Costa G.S.Casey A.R.Asplund M.Bessell M.S.,Frebel A.Keller S.C.Lind K.Mackey A.D.Murphy S.J.Nordlander T.,Norris J.E.Schmidt B.P.Yong D.2024-08-19T20:17:49Z2022-12-01T14:03:29ZCDS support team

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

cds-question@unistra.frchemical-abundancespopulation-ii-starschemically-peculiar-starsspectroscopyvisible-astronomyWe present results from the analysis of high-resolution spectra obtained with the Keck HIRES spectrograph for a sample of 17 candidate extremely metal-poor (EMP) stars originally selected from commissioning data obtained with the SkyMapper telescope. Fourteen of the stars have not been observed previously at high dispersion. Three have [Fe/H]=<-3.0, while the remainder, with two more metal-rich exceptions, have -3.0=<[Fe/H]=<-2.0dex. Apart from Fe, we also derive abundances for the elements C, N, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, and Zn, and for n-capture elements Sr, Ba, and Eu. None of the current sample of stars is found to be carbon-rich. In general, our chemical abundances follow previous trends found in the literature, although we note that two of the most metal-poor stars show very low [Ba/Fe] (~-1.7) coupled with low [Sr/Ba] (~-0.3). Such stars are relatively rare in the Galactic halo. One further star, and possibly two others, meet the criteria for classification as a r-I star. This study, together with that of Jacobson et al. (2015ApJ...807..171J, Cat. J/ApJ/807/171), completes the outcomes of the SkyMapper commissioning data survey for EMP stars.2019MNRAS.485.5153Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/485/5153CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/807/171 : SkyMapper Survey metal-poor star spectroscopyII/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/485/5153https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/485/5153http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/485/5153https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/485/5153https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/485/5153http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/485/5153GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/485/5153/table1 (Details of the target stars and the Keck HIRES observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/485/5153/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/485/5153/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/485/5153/table1?GETtext/xml+votable180.050000true305.2465417-4.57972220.0055555555555555566/18491 18612 18732 19022-19023 19083 19087 19109 29979 29983 30005 30021 35760 36098 46966 48240https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/485/5153?format=asciiOpticaldefaultJ/MNRAS/485/5153/table1Details of the target stars and the Keck HIRES observationsmiMetallicity index (1)phot.color;arith.difffloatTexpIntegration timestime.epochintSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.maingmagSkyMapper g-band magnitudemagphot.mag;em.opt.Bfloatg-ig-i colour indexmagphot.colorfloatS/N450Signal to noise ratio per pixel at 450nmpixel**-1stat.snrintS/N600Signal to noise ratio per pixel at 600nmpixel**-1stat.snrintRVRadial velocitykm/sphys.veloc;pos.heliocentricfloatNotes? Previous observations (2)meta.noteintnullableJ/MNRAS/485/5153/table2Adopted atmospheric parametersNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]LTELTE Iron to hydrogen abundance ratiophys.abund.Fefloat[Fe/H]nLTEIron to hydrogen abundance ratio obtained by applying non-LTE corrections to FeI linesphys.abund.FefloatvtMicroturbulence velocitykm/sphys.veloc.microTurbfloatJ/MNRAS/485/5153/table3Atomic data and EWs for program starsloggfTotal oscillator strength employedphys.atmol.oscStrengthfloatEWMeasured equivalent width0.0001nmspect.line.eqWidthfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharlambdaWavelenght of the spectral line used in the abundance analysis0.1nminstr.setup;spect.linedoubleSpeciesChemical species analysedmeta.notefloatEPExcitational potentialeVphys.energy;phys.atmol.excitationfloatJ/MNRAS/485/5153/table4Chemical abundance ratios for the light elements C, N, Na, and AlrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.mainchar[C/Fe]C to iron abundance ratiophys.abundfloate_[C/Fe]Error on [C/Fe]stat.error;phys.abundfloato_[C/Fe]Number of spectral features analysed for [C/Fe]meta.numberint[C/Fe]evolEvolutionary corrected [C/Fe] abundance (1)phys.abundfloat[N/Fe]? N to iron abundance ratiophys.abundfloatnullablee_[N/Fe]? Error on [N/Fe]stat.error;phys.abundfloatnullableo_[N/Fe]? Number of spectral features analysed for [N/Fe]meta.numberintnullable[Na/Fe]LTELTE [Na/Fe] abundancephys.abundfloate_[Na/Fe]LTEError on [Na/Fe]LTEstat.error;phys.abundfloat[Na/Fe]nLTEnon-LTE [Na/Fe] abundancephys.abundfloate_[Na/Fe]nLTEError on [Na/Fe]nLTEstat.error;phys.abundfloate_[Al/Fe]? Error on [Al/Fe]stat.error;phys.abundfloatnullableo_[Al/Fe]? Number of spectral features analysed for [Al/Fe]meta.numberintnullableo_[Na/Fe]LTENumber of spectral features analysed for [Na/Fe]LTEmeta.numberint[Al/Fe]? Al to iron abundance ratiophys.abundfloatnullableJ/MNRAS/485/5153/table5Chemical abundances for {alpha} elements, Mg, Si, Ca, and TirecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.mainchar[Mg/Fe]Mg to iron abundance ratiophys.abundfloate_[Mg/Fe]Error on [Mg/Fe]stat.error;phys.abundfloato_[Mg/Fe]Number of spectral features analysed for [Mg/Fe]meta.numberint[Si/Fe]Si to iron abundance ratiophys.abundfloate_[Si/Fe]? Error on [Si/Fe]stat.error;phys.abundfloatnullableo_[Si/Fe]Number of spectral features analysed for [Si/Fe]meta.numberint[Ca/Fe]? Ca to iron abundance ratiophys.abundfloatnullablee_[Ca/Fe]? Error on [Ca/Fe]stat.error;phys.abundfloatnullableo_[Ca/Fe]? Number of spectral features analysed for [Ca/Fe]meta.numberintnullable[TiI/Fe]? TiI to iron abundance ratiophys.abundfloatnullablee_[TiI/Fe]? Error on [TiI/Fe]stat.error;phys.abundfloatnullableo_[TiI/Fe]? Number of spectral features analysed for [TiI/Fe]meta.numberintnullable[TiII/Fe]TiII to iron abundance ratiophys.abundfloatf_[TiII/Fe]? Flag on [TiII/Fe] (1)meta.codeintnullablee_[TiII/Fe]Error on [TiII/Fe]stat.error;phys.abundfloato_[TiII/Fe]Number of spectral features analysed for [TiII/Fe]meta.numberintJ/MNRAS/485/5153/table6Chemical abundances for FeI and FeII, and Fe-peak elements Sc (ScII), Cr, Mn, Co, Ni, and Zne_[Zn/Fe]? Error on [Zn/Fe]stat.error;phys.abundfloatnullableo_[Zn/Fe]? Number of spectral features analysed for [Zn/Fe]meta.numberintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.mainchar[FeI/H]FeI to hydrogen abundance ratiophys.abund.Fefloate_[FeI/H]Error on [FeI/H]stat.error;phys.abundfloato_[FeI/H]Number of spectral features analysed for [FeI/H]meta.numberint[FeII/H]? FeII to iron abundance ratiophys.abund.Fefloatnullablee_[FeII/H]? Error on [FeII/H]stat.error;phys.abundfloatnullableo_[FeII/H]? Number of spectral features analysed for [FeII/H]meta.numberintnullable[Sc/Fe]? Sc to iron abundance ratiophys.abundfloatnullablee_[Sc/Fe]? Error on [Sc/Fe]stat.error;phys.abundfloatnullableo_[Sc/Fe]? Number of spectral features analysed for [Sc/Fe]meta.numberintnullable[CrI/Fe]? CrI to iron abundance ratiophys.abundfloatnullablee_[CrI/Fe]? Error on [CrI/Fe]stat.error;phys.abundfloatnullableo_[CrI/Fe]? Number of spectral features analysed for [CrI/Fe]meta.numberintnullable[CrII/Fe]? CrII to iron abundance ratiophys.abundfloatnullableo_[CrII/Fe]? Number of spectral features analysed for [CrII/Fe]meta.numberintnullable[Mn/Fe]Mn to iron abundance ratiophys.abundfloate_[Mn/Fe]Error on [Mn/Fe]stat.error;phys.abundfloato_[Mn/Fe]Number of spectral features analysed for [Mn/Fe]meta.numberint[Co/Fe]? Co to iron abundance ratiophys.abundfloatnullablee_[Co/Fe]? Error on [Co/Fe]stat.error;phys.abundfloatnullableo_[Co/Fe]? Number of spectral features analysed for [Co/Fe]meta.numberintnullable[Ni/Fe]? Ni to iron abundance ratiophys.abundfloatnullablee_[Ni/Fe]? Error on [Ni/Fe]stat.error;phys.abundfloatnullableo_[Ni/Fe]? Number of spectral features analysed for [Ni/Fe]meta.numberintnullable[Zn/Fe]? Zn to iron abundance ratiophys.abundfloatnullableJ/MNRAS/485/5153/table7Chemical abundances for the n-capture elements, Sr, Ba, and EurecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSkyMapper identifier (SMSS JHHMMSS.ss+DDMMSS.s)meta.id;meta.mainchar[Sr/Fe]Sr to iron abundance ratiophys.abundfloate_[Sr/Fe]Error on [Sr/Fe]stat.error;phys.abundfloato_[Sr/Fe]Number of spectral features analysed for [Sr/Fe]meta.numberintl_[Ba/Fe]Limit flag on [Ba/Fe]meta.code.error;phys.abundchar[Ba/Fe]Ba to iron abundance ratiophys.abundfloate_[Ba/Fe]Error on [Ba/Fe]stat.error;phys.abundfloato_[Ba/Fe]Number of spectral features analysed for [Ba/Fe]meta.numberintl_[Eu/Fe]Limit flag on [Eu/Fe]meta.code.error;phys.abundchar[Eu/Fe]Eu to iron abundance ratiophys.abundfloate_[Eu/Fe]? Error on [Eu/Fe]stat.error;phys.abundfloatnullableo_[Eu/Fe]? Number of spectral features analysed for [Eu/Fe]meta.numberintnullable