J/A+A/642/A176ivo://CDS.VizieR/J/A+A/642/A176doi:10.26093/cds/vizier.36420176CDSTheler R.Jablonka P.Lucchesi R.Lardo C.North P.Irwin M.,Battaglia G.Hill V.Tolstoy E.Venn K.Helmi A.Kaufer A.Primas F.,Shetrone M.2022-10-04T14:20:52Z2020-10-15T14:03:17ZCDS support team

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

cds-question@unistra.frgalaxieschemical-abundancesline-intensitiesradial-velocityeffective-temperatureWe present our analysis of the FLAMES dataset targeting the central 25' region of the Sextans dwarf spheroidal galaxy (dSph). This dataset is the third major part of the high-resolution spectroscopic section of the ESO large program 171.B-0588(A) obtained by the Dwarf galaxy Abundances and Radial-velocities Team (DART). Our sample is composed of red giant branch stars down to V~20.5mag, the level of the horizontal branch in Sextans, and allows users to address questions related to both stellar nucleosynthesis and galaxy evolution. We provide metallicities for 81 stars, which cover the wide [Fe/H]=-3.2 to -1.5dex range. The abundances of ten other elements are derived: Mg, Ca, Ti, Sc, Cr, Mn, Co, Ni, Ba, and Eu. Despite its small mass, Sextans is a chemically evolved system, showing evidence of a contribution from core-collapse and Type Ia supernovae as well as low-metallicity asymptotic giant branch stars (AGBs). This new FLAMES sample offers a sufficiently large number of stars with chemical abundances derived with high accuracy to firmly establish the existence of a plateau in [alpha/Fe] at ~0.4dex followed by a decrease above [Fe/H]~-2dex. These features reveal a close similarity with the Fornax and Sculptor dSphs despite their very different masses and star formation histories, suggesting that these three galaxies had very similar star formation efficiencies in their early formation phases, probably driven by the early accretion of smaller galactic fragments, until the UV-background heating impacted them in different ways. The parallel between the Sculptor and Sextans dSph is also striking when considering Ba and Eu. The same chemical trends can be seen in the metallicity region common to both galaxies, implying similar fractions of SNeIa and low-metallicity AGBs. Finally, as to the iron-peak elements, the decline of [Co/Fe] and [Ni/Fe] above [Fe/H]~-2 implies that the production yields of Ni and Co in SNeIa are lower than that of Fe. The decrease in [Ni/Fe] favours models of SNeIa based on the explosion of double-degenerate sub-Chandrasekhar mass white dwarfs.2020A&A...642A.176Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/642/A176CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/126/2840 : BVI CCD photometry of Sextans dSph galaxy (Lee+, 2003)J/MNRAS/411/1013 : CaII triplet in Sextans dSph galaxy (Battaglia+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/642/A176https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/642/A176http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/642/A176https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/642/A176https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/642/A176http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/642/A176GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/642/A176/table2 (Position, photometry and radial velocities of our targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/642/A176/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/642/A176/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/642/A176/table2?GETtext/xml+votable180.050000true153.173333-1.5476670.0055555555555555566/272078.297946179207444e-20 3.9865436196254505e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/642/A176?format=asciidefaultJ/A+A/642/A176/table2Position, photometry and radial velocities of our targetsDEJ2000Declination (J2000)pos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar IDmeta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainVmagESO/WFI V magnitudemagphot.mag;em.opt.VfloatImagESO/WFI I magnitudemagphot.mag;em.opt.IfloatJmagUKIRT/WFCAM J magnitudemagphot.mag;em.IR.JfloatHmagUKIRT/WFCAM H magnitudemagphot.mag;em.IR.HfloatKmag? UKIRT/WFCAM K magnitudemagphot.mag;em.IR.Kfloatnullablel_RV[~] Limit flag on RV, for probable binaries (1)meta.code.errorcharRVMean radial velocity (1)km/sphys.veloc;pos.heliocentricfloate_RVrms uncertainty on mean radial velocitykm/sstat.errorfloatComComments (2)meta.notecharJ/A+A/642/A176/table3Parameters derived from photometry for the probable members of our samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintT(V-I)[4011/5116] Effective temperature from V-IKphys.temperature.effectiveintT(V-J)[4179/5428] Effective temperature from V-JKphys.temperature.effectiveintT(V-H)[4026/5244] Effective temperature from V-HKphys.temperature.effectiveintT(V-K)[4199/5725]? Effective temperature from V-HKphys.temperature.effectiveintnullableBCVBolometric correctionmagphot.mag.bcfloatMbolBolometric magnitudemagphys.magAbs.bolfloat[Fe/H](CaT)Initial metallicity estimate from CaTphys.abund.Fefloate_[Fe/H](CaT)? rms uncertainty on [Fe/H](CaT)stat.errorfloatnullableS/NHR10[0/96] SNR in HR10 grismstat.snrintS/NHR13[0/141] SNR in HR13stat.snrintS/NHR14[0/144] SNR in HR14stat.snrintS/Nav[5/117] Average Signal-to-noise ratiostat.snr;stat.meanintIDStar IDmeta.id;meta.maincharJ/A+A/642/A176/table4The radial velocities measured by DAOSPEC in each of the HR10, HR13, HR14 setups, and their averagerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar IDmeta.id;meta.maincharRVHR10? Radial velocity in HR10km/sphys.veloc;pos.heliocentricfloatnullablee_RVHR10? rms uncertainty on RVHR10km/sstat.errorfloatnullableo_RVHR10? Number of used lines in HR10meta.numberintnullableRVHR13? Radial velocity in HR13km/sphys.veloc;pos.heliocentricfloatnullablee_RVHR13? rms uncertainty on RVHR13km/sstat.errorfloatnullableo_RVHR13? Number of used lines in HR13meta.numberintnullableRVHR14? Radial velocity in HR14km/sphys.veloc;pos.heliocentricfloatnullablee_RVHR14? rms uncertainty on RVHR14km/sstat.errorfloatnullableo_RVHR14? Number of used lines in HR14meta.numberintnullablel_RVmean[~] Limit flag on RVmean (1)meta.code.errorcharRVmeanMean radial velocity in HR10km/sspect.dopplerVeloc;stat.meanfloate_RVmeanrms uncertainty on RVHR10km/sstat.errorfloatJ/A+A/642/A176/table5Equivalent widths of the stars observed with UVESlog(gf)Oscillator strengthphys.atmol.oscStrengthfloatn_EW1[*] Note on EW1 (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength0.1nmem.wlfloatElElementphys.atmol.elementcharchiexExcitation potentialeVphys.atmol.excitationfloatEW1? S05-5 equivalent width0.1nmspect.line.widthintnullablee_EW1? rms uncertainty on EW10.1nmstat.errorfloatnullableEW2? S08-229 equivalent width0.1nmspect.line.widthintnullablee_EW2? rms uncertainty on EW20.1nmstat.errorfloatnullablen_EW2[*] Note on EW2 (1)meta.notecharJ/A+A/642/A176/table6Four stellar parameters for the probables members of our samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar IDmeta.id;meta.maincharTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloatvturbMicro-turbulence velocitykm/sphys.veloc.microTurbfloat[Fe/H]Metallicityphys.abund.Zfloate_[Fe/H]? rms uncertainty on [Fe/H]stat.error;phys.abund.FefloatnullableJ/A+A/642/A176/table9Complete line list used to derive all the atomic abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength0.1nmem.wldoubleElElementphys.atmol.elementcharn_ElNote on El (1)meta.notecharchiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Oscillator strengthphys.atmol.oscStrengthfloatC6C6 constantarith.zpdoubleJ/A+A/642/A176/table10*Atomic abundances for Fe, Mg, Ca and ScrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_ID[*] Note (1)meta.notechar[Fe/H]Metallicity with solar abundance log{epsilon}(X)_{sun}_=7.50phys.abund.Zfloate_[Fe/H]Systematic error on [Fe/H]stat.error;phys.abund.Fefloater_[Fe/H]Random error on [Fe/H]stat.error;phys.abundfloato_[Fe/H]Number of lines used to determined [Fe/H] abundancemeta.numberint[Mg/Fe]? Abundance [Mg/Fe] with solar abundance log{epsilon}(X)_{sun}_=7.58phys.abundfloatnullablee_[Mg/Fe]? Systematic error on [Mg/Fe]stat.error;phys.abundfloatnullableer_[Mg/Fe]? Random error on [Mg/Fe]stat.error;phys.abundfloatnullable[Ca/Fe]? Abundance [Ca/Fe] with solar abundance log{epsilon}(X)_{sun}_=6.36phys.abundfloatnullablee_[Ca/Fe]? Systematic error on [Ca/Fe]stat.error;phys.abundfloatnullableer_[Ca/Fe]? Random error on [Ca/Fe]stat.error;phys.abundfloatnullableo_[Ca/Fe]? Number of lines used to determined [Ca/Fe] abundancemeta.numberintnullable[Sc/Fe]? Abundance [Sc/Fe] with solar abundance log{epsilon}(X)_{sun}_=3.17phys.abundfloatnullablee_[Sc/Fe]? Systematic error on [Sc/Fe]stat.error;phys.abundfloatnullableer_[Sc/Fe]? Random error on [Sc/Fe]stat.error;phys.abundfloatnullableo_[Sc/Fe]? Number of lines used to determined [Sc/Fe] abundancemeta.numberintnullableIDStar IDmeta.id;meta.maincharJ/A+A/642/A176/table11*Atomic abundances for TiI, TiII, Cr and MnrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar IDmeta.id;meta.maincharn_ID[*] Note (1)meta.notechar[TiI/Fe]? Abundance [TiI/Fe] with solar abundance log{epsilon}(X)_{sun}_=5.02phys.abundfloatnullablee_[TiI/Fe]? Systematic error on [TiI/Fe]stat.error;phys.abundfloatnullableer_[TiI/Fe]? Random error on [TiI/Fe]stat.error;phys.abundfloatnullableo_[TiI/Fe]? Number of lines used to determined [TiI/Fe] abundancemeta.numberintnullable[TiII/Fe]? Abundance [TiII/Fe] with solar abundance log{epsilon}(X)_{sun}_=5.02phys.abundfloatnullablee_[TiII/Fe]? Systematic error on [TiII/Fe]stat.error;phys.abundfloatnullableer_[TiII/Fe]? Random error on [TiII/Fe]stat.error;phys.abundfloatnullableo_[TiII/Fe]? Number of lines used to determined [TiII/Fe] abundancemeta.numberintnullable[Cr/Fe]? Abundance [Cr/Fe] with solar abundance log{epsilon}(X)_{sun}_=5.67phys.abundfloatnullablee_[Cr/Fe]? Systematic error on [Cr/Fe]stat.error;phys.abundfloatnullableer_[Cr/Fe]? Random error on [Cr/Fe]stat.error;phys.abundfloatnullableo_[Cr/Fe]? Number of lines used to determined [Cr/Fe] abundancemeta.numberintnullable[Mn/Fe]? Abundance [Mn/Fe] with solar abundance log{epsilon}(X)_{sun}_=5.39phys.abundfloatnullablee_[Mn/Fe]? Systematic error on [Mn/Fe]stat.error;phys.abundfloatnullableer_[Mn/Fe]? Random error on [Mn/Fe]stat.error;phys.abundfloatnullableo_[Mn/Fe]? Number of lines used to determined [Mn/Fe] abundancemeta.numberintnullableJ/A+A/642/A176/table12*Atomic abundances for TiI, TiII, Cr and MnIDStar IDmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[Co/Fe]? Abundance [Co/Fe] with solar abundance log{epsilon}(X)_{sun}_=4.92phys.abundfloatnullablee_[Co/Fe]? Systematic error on [Co/Fe]stat.error;phys.abundfloatnullableer_[Co/Fe]? Random error on [Co/Fe]stat.error;phys.abundfloatnullable[NI/Fe]? Abundance [TiII/Fe] with solar abundance log{epsilon}(X)_{sun}_=6.25phys.abundfloatnullablee_[NI/Fe]? Systematic error on [NI/Fe]stat.error;phys.abundfloatnullableer_[NI/Fe]? Random error on [NI/Fe]stat.error;phys.abundfloatnullableo_[NI/Fe]? Number of lines used to determined [NI/Fe] abundancemeta.numberintnullable[Ba/Fe]? Abundance [Ba/Fe] with solar abundance log{epsilon}(X)_{sun}_=2.13phys.abundfloatnullablee_[Ba/Fe]? Systematic error on [Ba/Fe]stat.error;phys.abundfloatnullableer_[Ba/Fe]? Random error on [Ba/Fe]stat.error;phys.abundfloatnullableo_[Ba/Fe]? Number of lines used to determined [Ba/Fe] abundancemeta.numberintnullable[Eu/Fe]? Abundance [Eu/Fe] with solar abundance log{epsilon}(X)_{sun}_=5.39phys.abundfloatnullablee_[Eu/Fe]? Systematic error on [Eu/Fe]stat.error;phys.abundfloatnullableer_[Eu/Fe]? Random error on [Eu/Fe]stat.error;phys.abundfloatnullablen_ID[*] Note (1)meta.notecharJ/A+A/642/A176/table13Equivalent widths of the GIRAFFE sampleElElementphys.atmol.elementcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambdaWavelength0.1nmem.wlfloatchiexExcitation potentialeVphys.atmol.excitationfloatlog(gf)Oscillator strengthphys.atmol.oscStrengthfloatEW1? S08-3 equivalent width0.1nmspect.line.widthintnullablee_EW1? S08-3 equivalent width error0.1nmstat.errorfloatnullableEW2? S08-6 equivalent width0.1nmspect.line.widthintnullablee_EW2? S08-6 equivalent width error0.1nmstat.errorfloatnullableEW3? S05-10 equivalent width0.1nmspect.line.widthintnullablee_EW3? S05-10 equivalent width error0.1nmstat.errorfloatnullableEW4? S08-38 equivalent width0.1nmspect.line.widthintnullablee_EW4? S08-38 equivalent width error0.1nmstat.errorfloatnullableEW5? S08-239 equivalent width0.1nmspect.line.widthintnullablee_EW5? S08-239 equivalent width error0.1nmstat.errorfloatnullableEW6? S08-241 equivalent width0.1nmspect.line.widthintnullablee_EW6? s08-241 equivalent width error0.1nmstat.errorfloatnullableEW7? S08-242 equivalent width0.1nmspect.line.widthintnullablee_EW7? S08-242 equivalent width error0.1nmstat.errorfloatnullableEW8? S07-69 equivalent width0.1nmspect.line.widthintnullablee_EW8? S07-69 equivalent width error0.1nmstat.errorfloatnullableEW9? S08-59 equivalent width0.1nmspect.line.widthintnullablee_EW9? S08-59 equivalent width error0.1nmstat.errorfloatnullablen_EW9[*] Note on EW1 (1)meta.notecharEW10? S05-60 equivalent width0.1nmspect.line.widthintnullablee_EW10? S05-60 equivalent width error0.1nmstat.errorfloatnullableEW11? S08-246 equivalent width0.1nmspect.line.widthintnullablee_EW11? S08-246 equivalent width error0.1nmstat.errorfloatnullablen_EW11[*] Note on EW1 (1)meta.notecharEW12? S08-183 equivalent width0.1nmspect.line.widthintnullablee_EW12? S08-183 equivalent width error0.1nmstat.errorfloatnullablen_EW12[*] Note on EW12 (1)meta.notecharn_EW1[*] Note on EW1 (1)meta.notecharn_EW2[*] Note on EW1 (1)meta.notecharn_EW3[*] Note on EW1 (1)meta.notecharn_EW4[*] Note on EW1 (1)meta.notecharn_EW5[*] Note on EW1 (1)meta.notecharn_EW6[*] Note on EW1 (1)meta.notecharn_EW7[*] Note on EW1 (1)meta.notecharn_EW8[*] Note on EW1 (1)meta.notechar