J/MNRAS/482/1275ivo://CDS.VizieR/J/MNRAS/482/1275doi:10.26093/cds/vizier.74821275CDSUsher C.Beckwith T.Bellstedt S.Alabi A.Chevalier L.Pastorello N.,Cerulo P.Dalgleish H.S.Fraser-McKelvie A.Kamann S.Penny S.,Foster C.McDermid R.Schiavon R.P.Villaume A.2024-08-19T20:14:37Z2022-08-01T15:02:58ZCDS support team

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

cds-question@unistra.frchemical-abundancesglobular-star-clustersgalaxiesvisible-astronomyUsing data from the WiFeS Atlas of Galactic Globular cluster Spectra, we study the behaviour of the calcium triplet (CaT), a popular metallicity indicator in extragalactic stellar population studies. A major caveat of these studies is that the potential sensitivity to other stellar population parameters such as age, calcium abundance, and the initial mass function has not yet been empirically evaluated. Here, we present measurements of the strength of the CaT feature for 113 globular clusters in the Milky Way and its satellite galaxies. We derive empirical calibrations between the CaT index and both the iron abundance ([Fe/H]) and calcium abundance ([Ca/H]), finding a tighter relationship for [Ca/H] than for [Fe/H]. For stellar populations, 3Gyr and older the CaT can be used to reliably measure [Ca/H] at the 0.1dex level but becomes less reliable for ages of ~2Gyr and younger. We find that the CaT is relatively insensitive to the horizontal branch morphology. The stellar mass function however affects the CaT strengths significantly only at low metallicities. Using our newly derived empirical calibration, we convert our measured CaT indices into [Ca/H] values for the globular clusters in our sample.2019MNRAS.482.1275Uhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/482/1275CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/195 : Globular Clusters in the Milky Way (Harris, 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/482/1275https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/482/1275http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/482/1275https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/482/1275https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/482/1275http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/482/1275GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/482/1275/table1 (properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/482/1275/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/482/1275/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/482/1275/table1?GETtext/xml+votable180.050000true6.0223292-72.08144440.0055555555555555566/10336 12405 12425 12531 12943 16647 19091 21017 24843 25873 27981 28067 28705 28741 28751 28769 28778 28868 28882 28889 28959 28962 28970 28973-28974 29184 29187 29195 29216 29222 29231 29248 29267 29289 29294 29318 29377 29632 29816 29870 30769 31019 31043 31115 31417 32983 33077 33093-33094 33096-33098 33112-33113 33120 33123-33124 33127 33137-33138 33140 33287 33304 33306 33315 33317 33321 33323 33328 33330 33635 34242 35969 37294 37514 38465 39642 41011 41304 41522 41847 41852 42076 42278 42314 42320 42700 42761 42841 42955 42958 42990 43125 43227 44086 44220 47125 47620 47777 47825 47866 47868 47971 48035 48434 48698 48952https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/482/1275?format=asciiOpticaldefaultJ/MNRAS/482/1275/table1propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGlobular cluster designationmeta.id;meta.maincharGalaxyHost galaxy (1)src.class.starGalaxychar[Fe/H]Literature metallicityphys.abund.ZfloatAge? Literature ageGyrtime.agefloatnullableRcCore radiusarcsecphys.angSizefloatRh? Half-light radiusarcsecphys.angSizefloatnullablemuVCentral surface brightness in V bandmag.arcsec**-2phot.mag.sbfloatAVV band extinctionmagphys.absorptionfloatMassStellar masslog(solMass)phys.massfloatMassInStellar mass in observed field-of-viewlog(solMass)phys.massfloatr_[Fe/H]Reference for metallicity (2)meta.refcharr_AgeReference for age (2)meta.ref;pos.framecharrefstrReferences for structural parameters (2)meta.ref;pos.framecharSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/MNRAS/482/1275/table2Adopted high-resolution abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGlobular cluster designationmeta.id;meta.mainchar[Fe/H]Iron abundancephys.abund.Fefloate_[Fe/H]Error on [Fe/H]stat.error;phys.abund.Fefloat[Ca/Fe]? Calcium to Iron ratiophys.abundfloatnullablee_[Ca/Fe]? Error on [Ca/Fe]stat.error;phys.abundfloatnullableRefList of ADS bibcodes for abundance referencesmeta.notecharJ/MNRAS/482/1275/table5CaT measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameGlobular cluster designationmeta.id;meta.maincharRVRadial velocitykm/sphys.veloc;pos.heliocentricdoublee_RVLower error on RVkm/sstat.errorfloatE_RVUpper error on RVkm/sstat.error;stat.maxfloatCaTCalcium triplet strength0.1nmphys.atmol.collStrengthfloate_CaTLower error on CaT0.1nmstat.errorfloatE_CaTUpper error on CaT0.1nmstat.error;stat.maxfloat[Ca/H]Calcium triplet based Ca abundancephys.abundfloate_[Ca/H]Lower error on [Ca/H]stat.error;phys.abundfloatE_[Ca/H]Upper error on [Ca/H]stat.error;stat.maxfloatAgeFlag[0,1] Age flag (0: ok, 1: Ca measurement less reliable due to age <3Gyr)meta.codeintMassFlag[0,1] Mass flag (0: ok, 1: Ca measurement less reliable due to Mass<5x10^3^M_{sun}_ in observed field-of-view)meta.codeint