J/MNRAS/446/369ivo://CDS.VizieR/J/MNRAS/446/369doi:10.26093/cds/vizier.74460369CDSUsher C.Forbes D.A.Brodie J.P.Romanowsky A.J.Strader J.Conroy C.,Foster C.Pastorello N.Pota V.Arnold J.A.2024-08-14T20:19:10Z2017-11-09T07:31:51ZCDS support team

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

cds-question@unistra.frgalaxiesglobular-star-clustersstellar-populationstwo-color-diagramsabsolute-magnitudespectroscopysurveysAs part of the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey, we stack 1137 Keck DEIMOS (Deep Imaging Multi-Object Spectrograph) spectra of globular clusters from 10 galaxies to study their stellar populations in detail. The stacked spectra have median signal-to-noise ratios of ~90 {AA}^-1^. Besides the calcium triplet, we study weaker sodium, magnesium, titanium and iron lines as well as the H{alpha} and higher order Paschen hydrogen lines. In general, the stacked spectra are consistent with old ages and a Milky Way-like initial mass function. However, we see different metal line index strengths at fixed colour and magnitude, and differences in the calcium triplet-colour relation from galaxy to galaxy. We interpret this as strong evidence for variations in the globular cluster colour-metallicity relation between galaxies. Two possible explanations for the colour-metallicity relation variations are that the average ages of globular clusters vary from galaxy to galaxy or that the average abundances of light elements (i.e. He, C, N and O) differ between galaxies. Stacking spectra by magnitude, we see that the colours become redder and metal line indices stronger with brighter magnitudes. These trends are consistent with the previously reported `blue tilts' being mass-metallicity relations.2015MNRAS.446..369Uhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/446/369CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/MNRAS/355/608 : NGC 4649 (M60) globular clusters (Forbes+, 2004)J/A+A/455/453 : Globular Cluster System of NGC5846 (Chies-Santos+, 2006)J/ApJ/655/144 : ACS Virgo Cluster Survey. XIII. (Mei+, 2007)J/AJ/137/4956 : Globular clusters around NGC 1407 (Romanowsky+, 2009)J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)J/MNRAS/420/37 : NGC 4365 globular clusters (Blom+, 2012)J/MNRAS/426/1475 : CaT in 903 globular clusters (Usher+, 2012)J/MNRAS/428/389 : SLUGGS globular clusters in early-type galaxiesJ/MNRAS/436/1172 : Globular Clusters of NGC 4278 in SLUGGS (Usher+, 2013)J/AJ/148/32 : Globular cluster candidates in NGC 3115 (Jennings+, 2014)J/MNRAS/452/2208 : NGC 4473 globular clusters (Alabi+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/446/369https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/446/369http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/446/369https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/446/369https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/446/369http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/446/369GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/446/369/table1 (Galaxy properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/446/369/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/446/369/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/446/369/table1?GETtext/xml+votable180.050000true55.0496-18.580377780.0055555555555555566/7385 8196 26803 27604 27718 27907 27938 28142 28495 36247https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/446/369?format=asciiOpticaldefaultJ/MNRAS/446/369/table1Galaxy propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNGC[1407/5846] Host galaxy namemeta.id;meta.mainintn_NGC[a] Note on NGC (1)meta.notecharRAJ2000Simbad Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Simbad Degree of Declination (J2000)pos.eq.dec;meta.mainVsysSystemic velocity from Cappellari et al. (2011, J/MNRAS/413/813)km/sphys.velocintDistDistance from Cappellari et al. (2011, J/MNRAS/413/813) (2)Mpcpos.distance;pos.heliocentricfloatKMagK-band absolute magnitude from Cappellari et al. (2011, J/MNRAS/413/813) (3)magphot.mag;em.IR.KfloatSpectraTotal number of GC spectrameta.numberintGCNumber of unique GCs with spectrameta.numberintSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/446/369/tablea1Colour and spectral index measurements of spectra stacked by colour for galaxiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNGC[1407/5846]? Host galaxy namemeta.id;meta.mainintnullableg-iSubaru/Suprime-Cam (g-i) colour indexmagphot.color;em.opt.B;em.opt.IfloatE_g-iUpper limit uncertainty in g-imagstat.error;stat.maxfloate_g-iLower limit uncertainty in g-imagstat.errorfloatiMagSubaru/Suprime-Cam i-band absolute magnitudemagphys.magAbsfloatE_iMagUpper limit uncertainty in iMagmagstat.error;stat.maxfloate_iMagLower limit uncertainty in iMagmagstat.error;phot.magfloatCaTCa II triplet spectral index strength ({AA})0.1nmspect.indexfloatE_CaTUpper limit uncertainty in CaT0.1nmstat.error;stat.maxfloate_CaTLower limit uncertainty in CaT0.1nmstat.errorfloatFe86Fe86 spectral index strength ({AA})0.1nmspect.indexfloatE_Fe86Upper limit uncertainty in Fe860.1nmstat.error;stat.maxfloate_Fe86Lower limit uncertainty in Fe860.1nmstat.errorfloatMg88Mg88 spectral index strength ({AA})0.1nmspect.indexfloatE_Mg88Upper limit uncertainty in Mg880.1nmstat.error;stat.maxfloate_Mg88Lower limit uncertainty in Mg880.1nmstat.errorfloatNa82Na82 spectral index strength ({AA})0.1nmspect.indexfloatE_Na82Upper limit uncertainty in Na820.1nmstat.error;stat.maxfloate_Na82Lower limit uncertainty in Na820.1nmstat.errorfloatTiO89TiO89 spectral index strengthspect.indexfloatE_TiO89Upper limit uncertainty in TiO89stat.error;stat.maxfloate_TiO89Lower limit uncertainty in TiO89stat.errorfloatHalphaH{alpha} spectral index strength ({AA})0.1nmspect.index;em.line.HalphafloatE_HalphaUpper limit uncertainty in Halpha0.1nmstat.error;stat.maxfloate_HalphaLower limit uncertainty in Halpha0.1nmstat.errorfloatPaTPaschen line spectral index strength ({AA})0.1nmspect.indexfloatE_PaTUpper limit uncertainty in PaT0.1nmstat.error;stat.maxfloate_PaTLower limit uncertainty in PaT0.1nmstat.errorfloatJ/MNRAS/446/369/tablea2Colour and spectral index measurements of spectra stacked by colour for groupsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGroup[faint bright] Galaxy group (1)meta.idcharg-iSubaru/Suprime-Cam (g-i) colour indexmagphot.color;em.opt.B;em.opt.IfloatE_g-iUpper limit uncertainty in g-imagstat.error;stat.maxfloate_g-iLower limit uncertainty in g-imagstat.errorfloatiMagSubaru/Suprime-Cam i-band absolute magnitudemagphys.magAbsfloatE_iMagUpper limit uncertainty in iMagmagstat.error;stat.maxfloate_iMagLower limit uncertainty in iMagmagstat.error;phot.magfloatCaTCa II triplet spectral index strength ({AA})0.1nmspect.indexfloatE_CaTUpper limit uncertainty in CaT0.1nmstat.error;stat.maxfloate_CaTLower limit uncertainty in CaT0.1nmstat.errorfloatFe86Fe86 spectral index strength ({AA})0.1nmspect.indexfloatE_Fe86Upper limit uncertainty in Fe860.1nmstat.error;stat.maxfloate_Fe86Lower limit uncertainty in Fe860.1nmstat.errorfloatMg88Mg88 spectral index strength ({AA})0.1nmspect.indexfloatE_Mg88Upper limit uncertainty in Mg880.1nmstat.error;stat.maxfloate_Mg88Lower limit uncertainty in Mg880.1nmstat.errorfloatNa82Na82 spectral index strength ({AA})0.1nmspect.indexfloatE_Na82Upper limit uncertainty in Na820.1nmstat.error;stat.maxfloate_Na82Lower limit uncertainty in Na820.1nmstat.errorfloatTiO89TiO89 spectral index strengthspect.indexfloatE_TiO89Upper limit uncertainty in TiO89stat.error;stat.maxfloate_TiO89Lower limit uncertainty in TiO89stat.errorfloatHalphaH{alpha} spectral index strength ({AA})0.1nmspect.index;em.line.HalphafloatE_HalphaUpper limit uncertainty in Halpha0.1nmstat.error;stat.maxfloate_HalphaLower limit uncertainty in Halpha0.1nmstat.errorfloatPaTPaschen line spectral index strength ({AA})0.1nmspect.indexfloatE_PaTUpper limit uncertainty in PaT0.1nmstat.error;stat.maxfloate_PaTLower limit uncertainty in PaT0.1nmstat.errorfloatsigma? Velocity dispersionkm/sphys.veloc.dispersionfloatnullableE_sigma? Upper limit uncertainty in sigmakm/sstat.error;stat.maxfloatnullablee_sigma? Lower limit uncertainty in sigmakm/sstat.errorfloatnullable