J/A+A/608/A145ivo://CDS.VizieR/J/A+A/608/A145doi:10.26093/cds/vizier.36080145CDSBattaglia G.North P.L.Jablonka P.Shetrone M.Minniti D.Diaz M.,Starkenburg E.Savoy M.2020-09-30T07:47:53Z2017-12-18T07:10:54ZCDS support team

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

cds-question@unistra.frmilky-way-galaxygiant-starschemical-abundancesIn a framework where galaxies form hierarchically, extended stellar haloes are predicted to be an ubiquitous feature around Milky Way-like galaxies and to consist mainly of the shredded stellar component of smaller galactic systems. The type of accreted stellar systems are expected to vary according to the specific accretion and merging history of a given galaxy, and so is the fraction of stars formed in-situ versus accreted. Analysis of the chemical properties of Milky Way halo stars out to large Galactocentric radii can provide important insights into the properties of the environment in which the stars that contributed to the build-up of different regions of the Milky Way stellar halo formed. In this work we focus on the outer regions of the Milky Way stellar halo, by determining chemical abundances of halo stars with large present-day Galactocentric distances, >15 kpc. The data-set we acquired consists of high resolution HET/HRS, Magellan/MIKE and VLT/UVES spectra for 28 red giant branch stars covering a wide metallicity range, -3.1<[Fe/H]<-0.6. We show that the ratio of alpha-elements over Fe as a function of [Fe/H] for our sample of outer halo stars is not dissimilar from the pattern shown by MW halo stars from solar neighborhood samples. On the other hand, significant differences appear at [Fe/H]>-1.5 when considering chemical abundance ratios such as [Ba/Fe], [Na/Fe], [Ni/Fe], [Eu/Fe], [Ba/Y]. Qualitatively, this type of chemical abundance trends are observed in massive dwarf galaxies, such as Sagittarius and the Large Magellanic Cloud. This appears to suggest a larger contribution in the outer halo of stars formed in an environment with high initial star formation rate and already polluted by asymptotic giant branch stars with respect to inner halo samples.2017A&A...608A.145Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/608/A145CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/608/A145https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/608/A145http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/608/A145https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/608/A145https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/608/A145http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/608/A145GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/608/A145/tablea2 (Coordinates, magnitude, distance and velocity of the stars in the sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/608/A145/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/608/A145/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/608/A145/tablea2?GETtext/xml+votable180.050000true145.72273617611.0644125090.0055555555555555566/4354-4355 12320 17307 17315 18359 19328 23174 25160 25177 25265 25416 25476 25561 25949 26116 26165 26168 26208 26467 27038 27499 28117 488921.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/608/A145?format=asciidefaultJ/A+A/608/A145/tablea5Lines parameters, observed equivalent widths and abundances of stars #1, #2, #3, #4, and #21 observed with HRSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement designationmeta.id;meta.maincharIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintlambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW01? Observed equivalent width of star #010.1pmspect.line.eqWidthfloatnullablee_EW01? Error on EW010.1pmstat.errorfloatnullableAbund01? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW02? Observed equivalent width of star #020.1pmspect.line.eqWidthfloatnullablee_EW02? Error on EW020.1pmstat.errorfloatnullableAbund02? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW03? Observed equivalent width of star #030.1pmspect.line.eqWidthfloatnullablee_EW03? Error on EW030.1pmstat.errorfloatnullableAbund03? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW04? Observed equivalent width of star #040.1pmspect.line.eqWidthfloatnullablee_EW04? Error on EW040.1pmstat.errorfloatnullableAbund04? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW21? Observed equivalent width of star #210.1pmspect.line.eqWidthfloatnullablee_EW21? Error on EW210.1pmstat.errorfloatnullableAbund21? log of the abundance (H abundance = 12.00)phys.abundfloatnullableJ/A+A/608/A145/tablea6Lines parameters, observed equivalent widths and abundances of stars #26, #5, #6, #7, and #28 observed with HRSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElementElement designationmeta.id;meta.maincharIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintlambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW26? Observed equivalent width of star #260.1pmspect.line.eqWidthfloatnullablee_EW26? Error on EW260.1pmstat.errorfloatnullableAbund26? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW05? Observed equivalent width of star #050.1pmspect.line.eqWidthfloatnullablee_EW05? Error on EW050.1pmstat.errorfloatnullableAbund05? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW06? Observed equivalent width of star #060.1pmspect.line.eqWidthfloatnullablee_EW06? Error on EW060.1pmstat.errorfloatnullableAbund06? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW07? Observed equivalent width of star #070.1pmspect.line.eqWidthfloatnullablee_EW07? Error on EW070.1pmstat.errorfloatnullableAbund07? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW28? Observed equivalent width of star #280.1pmspect.line.eqWidthfloatnullablee_EW28? Error on EW280.1pmstat.errorfloatnullableAbund28? log of the abundance (H abundance = 12.00)phys.abundfloatnullableJ/A+A/608/A145/tablea7Lines parameters, observed equivalent widths and abundances of stars #8, #9, #10, #11, and #12 observed with MIKEAbund11? log of the abundance (H abundance = 12.00)phys.abundfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement designationmeta.id;meta.maincharIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintLambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW08? Observed equivalent width of star #080.1pmspect.line.eqWidthfloatnullablee_EW08? Error on EW080.1pmstat.errorfloatnullableAbund08? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW09? Observed equivalent width of star #090.1pmspect.line.eqWidthfloatnullablee_EW09? Error on EW090.1pmstat.errorfloatnullableAbund09? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW10? Observed equivalent width of star #100.1pmspect.line.eqWidthfloatnullablee_EW10? Error on EW100.1pmstat.errorfloatnullablel_Abund10Limit flag on Abund10meta.code.errorcharAbund10? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW11? Observed equivalent width of star #110.1pmspect.line.eqWidthfloatnullablee_EW11? Error on EW110.1pmstat.errorfloatnullableEW12? Observed equivalent width of star #120.1pmspect.line.eqWidthfloatnullablee_EW12? Error on EW120.1pmstat.errorfloatnullablel_Abund12Limit flag on Abund12meta.code.errorcharAbund12? log of the abundance (H abundance = 12.00)phys.abundfloatnullableJ/A+A/608/A145/tablea10Lines parameters, observed equivalent widths and abundances of stars #19, #20, #21, #22, and #23 observed with UVESrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement designationmeta.id;meta.maincharIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintlambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW19? Observed equivalent width of star #190.1pmspect.line.eqWidthfloatnullablee_EW19? Error on EW190.1pmstat.errorfloatnullableAbund19? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW20? Observed equivalent width of star #200.1pmspect.line.eqWidthfloatnullablee_EW20? Error on EW200.1pmstat.errorfloatnullableAbund20? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW21? Observed equivalent width of star #210.1pmspect.line.eqWidthfloatnullablee_EW21? Error on EW210.1pmstat.errorfloatnullableAbund21? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW22? Observed equivalent width of star #220.1pmspect.line.eqWidthfloatnullablee_EW22? Error on EW220.1pmstat.errorfloatnullableAbund22? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW23? Observed equivalent width of star #230.1pmspect.line.eqWidthfloatnullablee_EW23? Error on EW230.1pmstat.errorfloatnullablel_Abund23Limit flag on Abund23meta.code.errorcharAbund23? log of the abundance (H abundance = 12.00)phys.abundfloatnullableJ/A+A/608/A145/tablea1Atmospheric stellar parameters and details of observations for the starse_RV1rms uncertainty on RV1km/sstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/28] Star sequential number (1)meta.recordintTeffSpectroscopic effective temperatureKphys.temperature.effectiveint[Fe/H]Metallicity of the atmosphere modelphys.abund.Z;meta.modelledfloatloggSpectroscopic surface gravitylog(cm.s**-2)phys.gravityfloatvturbMicroturbulence velocitykm/sphys.veloc.microTurbfloatloggphPhotometric surface gravitylog(cm.s**-2)phys.gravityfloate_loggphrms uncertainty on loggph (2)log(cm.s**-2)stat.errorfloatJDIntDays of the first and last exposuresmeta.notechartexpTotal exposure timestime.duration;obs.exposureintRVavgAverage radial velocity of all exposureskm/sphys.veloc;pos.heliocentricfloate_RVavgrms uncertainty on RVavgkm/sstat.errorfloatS/N4000? Signal-to-noise ratios at ~4000{AA}stat.snrintnullableS/N4900Signal-to-noise ratios at ~4900{AA}stat.snrintS/N6700Signal-to-noise ratios at ~6700{AA}stat.snrintInstInstrumentmeta.id;instrcharJD1Julian day for the middle of the exposuredtime.epochdoubleRV1Radial velocity of JD1 exposurekm/sspect.dopplerVeloc;obs.exposurefloatJD2? Julian day for the middle of the exposuredtime.epochdoublenullableRV2? Radial velocity of JD2 exposurekm/sspect.dopplerVeloc;obs.exposurefloatnullablee_RV2? rms uncertainty on RV2km/sstat.errorfloatnullableJD3? Julian day for the middle of the exposuredtime.epochdoublenullableRV3? Radial velocity of JD3 exposurekm/sspect.dopplerVeloc;obs.exposurefloatnullablee_RV3? rms uncertainty on RV3km/sstat.errorfloatnullableJD4? Julian day for the middle of the exposuredtime.epochdoublenullableRV4? Radial velocity of JD4 exposurekm/sspect.dopplerVeloc;obs.exposurefloatnullablee_RV4? rms uncertainty on RV4km/sstat.errorfloatnullableJD5? Julian day for the middle of the exposuredtime.epochdoublenullableRV5? Radial velocity of JD5 exposurekm/sspect.dopplerVeloc;obs.exposurefloatnullablee_RV5? rms uncertainty on RV5km/sstat.errorfloatnullableJ/A+A/608/A145/tablea2Coordinates, magnitude, distance and velocity of the stars in the sampleNameStar namemeta.id;meta.maincharComCommentsmeta.notecharSubSubstructuremeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAbundDisplay the abundancesmeta.ref.urlcharSeq[1/28] Star sequential numbermeta.recordintSourceGaia source IDmeta.idRA_ICRSGaia right ascension (ICRS) at epoch 2015.0degpos.eq.ra;meta.mainDE_ICRSGaia declination (ICRS) at epoch 2015.0degpos.eq.dec;meta.mainGLONGaia Galactic longitude at epoch 2015.0degpos.galactic.lonGLATGaia Galactic latitude at epoch 2015.0degpos.galactic.latdoubleGmagGaia G-band mean magnitudemagphot.mag;em.optfloatdH? Heliocentric distancekpcpos.distance;pos.heliocentricfloatnullableRgal? Galactocentric distancekpcpos.distance;pos.galactocentricfloatnullableVGSR? Galactic Standard of Rest velocitykm/sphys.veloc;pos.galacticfloatnullableLambda? Longitude in a system aligned with the Sag streamdegpos.earth.londoublenullableB? Latitude in a system aligned with the Sag streamdegpos.framedoublenullableFileName of the table with abundancesmeta.id;phys.abund;meta.tablechar_RA.icrsRight ascension (ICRS) at Epoch=J2015. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2015. (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexedJ/A+A/608/A145/tablea8Lines parameters, observed equivalent widths and abundances of stars #13, #14, #15, #16, and #17 observed with MIKErecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement designationmeta.id;meta.maincharIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintlambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW13? Observed equivalent width of star #130.1pmspect.line.eqWidthfloatnullablee_EW13? Error on EW130.1pmstat.errorfloatnullableAbund13? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW14? Observed equivalent width of star #140.1pmspect.line.eqWidthfloatnullablee_EW14? Error on EW140.1pmstat.errorfloatnullableAbund14? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW15? Observed equivalent width of star #150.1pmspect.line.eqWidthfloatnullablee_EW15? Error on EW150.1pmstat.errorfloatnullableAbund15? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW16? Observed equivalent width of star #160.1pmspect.line.eqWidthfloatnullablee_EW16? Error on EW160.1pmstat.errorfloatnullableAbund16? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW17? Observed equivalent width of star #170.1pmspect.line.eqWidthfloatnullablee_EW17? Error on EW170.1pmstat.errorfloatnullableAbund17? log of the abundance (H abundance = 12.00)phys.abundfloatnullableJ/A+A/608/A145/tablea9Lines parameters, observed equivalent widths and abundances of star #18 observed with MIKErecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement designationmeta.id;meta.maincharIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintlambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW18Observed equivalent width of star #180.1pmspect.line.eqWidthfloate_EW18Error on EW180.1pmstat.errorfloatAbund18log of the abundance (H abundance = 12.00)phys.abundfloatJ/A+A/608/A145/tablea11Lines parameters, observed equivalent widths and abundances of stars #24, #25, #26, #27, and #28 observed with UVESElElement designationmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonIonization state (1: neutral, 2: once ionized)phys.atmol.ionStageintlambdaLaboratory line wavelength0.1nmem.wl;spect.linedoubleChiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Statistical weight times oscillator strengthstat.weight;phys.atmol.oscStrengthfloatEW24? Observed equivalent width of star #240.1pmspect.line.eqWidthfloatnullablee_EW24? Error on EW240.1pmstat.errorfloatnullableAbund24? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW25? Observed equivalent width of star #250.1pmspect.line.eqWidthfloatnullablee_EW25? Error on EW250.1pmstat.errorfloatnullableAbund25? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW26? Observed equivalent width of star #260.1pmspect.line.eqWidthfloatnullablee_EW26? Error on EW260.1pmstat.errorfloatnullableAbund26? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW27? Observed equivalent width of star #270.1pmspect.line.eqWidthfloatnullablee_EW27? Error on EW270.1pmstat.errorfloatnullableAbund27? log of the abundance (H abundance = 12.00)phys.abundfloatnullableEW28? Observed equivalent width of star #280.1pmspect.line.eqWidthfloatnullablee_EW28? Error on EW280.1pmstat.errorfloatnullableAbund28? log of the abundance (H abundance = 12.00)phys.abundfloatnullable