J/AJ/152/208ivo://CDS.VizieR/J/AJ/152/208doi:10.26093/cds/vizier.51520208CDSFan Z.de Grijs R.Chen B.Jiang L.Bian F.Li Z.2017-09-04T08:02:22Z2017-06-01T09:02:56ZCDS support team

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

cds-question@unistra.frgalaxiesglobular-star-clustersradial-velocitymetallicityApplication of fitting techniques to obtain physical parameters-such as ages, metallicities, and {alpha}-element to iron ratios-of stellar populations is an important approach to understanding the nature of both galaxies and globular clusters (GCs). In fact, fitting methods based on different underlying models may yield different results and with varying precision. In this paper, we have selected 22 confirmed M31 GCs for which we do not have access to previously known spectroscopic metallicities. Most are located at approximately one degree (in projection) from the galactic center. We performed spectroscopic observations with the 6.5m MMT telescope, equipped with its Red Channel Spectrograph. Lick/IDS absorption-line indices, radial velocities, ages, and metallicities were derived based on the EZ_Ages stellar population parameter calculator. We also applied full spectral fitting with the ULySS code to constrain the parameters of our sample star clusters. In addition, we performed {chi}_min_^2^ fitting of the clusters' Lick/IDS indices with different models, including the Bruzual & Charlot models (adopting Chabrier or Salpeter stellar initial mass functions and 1994 or 2000 Padova stellar evolutionary tracks), the galev, and the Thomas et al. models. For comparison, we collected their UVBRIJK photometry from the Revised Bologna Catalogue (v.5) to obtain and fit the GCs' spectral energy distributions (SEDs). Finally, we performed fits using a combination of Lick/IDS indices and SEDs. The latter results are more reliable and the associated error bars become significantly smaller than those resulting from either our Lick/IDS indices-only or our SED-only fits.2016AJ....152..208Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/152/208CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/143 : Revised Bologna Catalog of M31 clusters, V.5 (Galleti+ 2012)J/AJ/152/45 : LAMOST survey of star clusters in M31. II. (Chen+, 2016)J/AJ/141/61 : Star clusters in M31. II. (Caldwell+, 2011)J/MNRAS/404/1639 : MILES base models & new line index system (Vazdekis+, 2010)J/MNRAS/402/803 : M31 globular cluster system (Peacock+, 2010)J/ApJ/725/200 : Updated catalog of M31 globular-like clusters (Fan+, 2010)J/AJ/139/1438 : SED and age estimates of M31 globular clusters (Wang+, 2010)J/A+A/508/1285 : Metallicity estimates of M31 GCs (Galleti+, 2009)J/A+A/456/985 : Radial velocities of M31 candidate clusters (Galleti+, 2006)J/MNRAS/372/1259 : Abundances of extragalactic GCs (Sharina+, 2006)J/AJ/123/2490 : RV and [Fe/H] of M31 GC system (Perrett+, 2002)J/AJ/122/2458 : M31 globular clusters from HST (Barmby+, 2001)J/AJ/119/727 : M31 globular clusters photometry (Barmby+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/152/208https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/152/208http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/152/208https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/152/208https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/152/208http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/152/208GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/152/208/clusters (Observations (table1), velocities (table2), and ages and metallicities (tables 3-6))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/152/208/clusters?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/152/208/clusters?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/152/208/clusters?GETtext/xml+votable180.050000true8.571762537.512061110.0055555555555555566/2597 2598 2607 2612 2616 2619 2621 2622 2664 2666 2667 2705 2708 2710 27523.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/152/208?format=asciiOpticaldefaultJ/AJ/152/208/clustersObservations (table1), velocities (table2), and ages and metallicities (tables 3-6)SimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (1)pos.eq.dec;meta.mainRpProjected radius from the galaxy center (r_p_) (1)kpcpos.distancefloatVmagV-band magnitude (1)magphot.mag;em.opt.VfloatExpExposure time of individual observationstime.duration;obs.exposureintNexp? Number of exposuresmeta.numberintnullableDateDate of observationtime.epochnullableNameGlobular cluster identificationmeta.id;meta.maincharf_Name[1a] Flag on Name (2)meta.codecharRV1[-673/45] Radial velocity fitted with ULySS based on the model of Vazdekis et al. 2010 (Cat. J/MNRAS/404/1639) (3)km/sspect.dopplerVeloc;meta.modelledinte_RV1[1/120] Uncertainty in RV1 (3)km/sstat.errorintRV2[-681/54] Radial velocity fitted with ULySS based on the PEGASE-HR model (3)km/sspect.dopplerVeloc;meta.modelledinte_RV2[1/60] Uncertainty in RV2 (3)km/sstat.errorintRV3[-561/33]? Radial velocity from the Revised Bologna Catalog (RBC) v.5. (Galleti et al. 2012, Cat. V/143)km/sspect.dopplerVelocintnullablee_RV3[1/47]? Uncertainty in RV3km/sstat.errorintnullablef_RV3[a] Flag 'a' on RV3 indicates that the RBC radial velocity was modified in -188+/-26km/s at CDS (4)meta.codecharlogAge1[9.3/10.25] Log of age for the Vazdekis et al. 2010 (Cat. J/MNRAS/404/1639) SSP model (5)yrtime.agefloate_logAge1[0/0.07] Error in logAge1 (5)yrstat.errorfloatlogAge2[9.4/10.4] Log of age for the PEGASE-HR SSP model (6)yrtime.agefloate_logAge2[0/0.042] Error in logAge2 (6)yrstat.errorfloat[Fe/H]1[-2.32/-0.35] Metallicity for the Vazdekis et al. 2010 (Cat. J/MNRAS/404/1639) SSP model (5)log(Sun)phys.abund.Zfloate_[Fe/H]1[0.01/0.04] Error in [Fe/H]1 (5)log(Sun)stat.error;phys.abund.Fefloat[Fe/H]2[-2.3/-0.4] Metallicity for the PEGASE-HR SSP model (6)log(Sun)phys.abund.Zfloate_[Fe/H]2[0.01/0.03] Error in [Fe/H]2 (6)log(Sun)stat.error;phys.abund.FefloatlogAge3[2/12.21]? Age derived with EZ_Ages (7)Gyrtime.agefloatnullable[Fe/H]3[-1.12/-0.18]? Metallicity derived with EZ_Ages (7)log(Sun)phys.abund.Zfloatnullable[Fe/H]4[-2.25/-0.35] Metallicity derived from [MgFe] (8)log(Sun)phys.abund.Zfloat[Fe/H]5[-2.95/-0.39] Metallicity derived from <Fe> (9)log(Sun)phys.abund.ZfloatlogAge4[8/10.2] Log of age derived from the Lick absorption-line index fitted with the Thomas et al. 2011MNRAS.412.2183T models (10)yrtime.agefloate_logAge4[0/0.22] Negative error in logAge4yrstat.errorfloatE_logAge4[0/0.19] Positive error in logAge4yrstat.error;stat.maxfloat[Z/H][-2.2/-0.29] Metallicity derived from the Lick absorption-line index fitted with the Thomas et al. 2011MNRAS.412.2183T models (10)log(Sun)phys.abund.Zfloate_[Z/H][0.09/0.47] Negative error in [Z/H]log(Sun)stat.error;src.redshiftfloatE_[Z/H][0.1/0.75] Positive error in [Z/H]log(Sun)stat.error;stat.maxfloat[a/Fe][-0.3/0.5] [{alpha}/Fe] ratio derived from the Lick absorption-line index fitted with the Thomas et al. 2011MNRAS.412.2183T models (10)log(Sun)phys.abundfloate_[a/Fe][0/0.8] Negative error in [a/Fe]log(Sun)stat.error;phys.abundfloatE_[a/Fe][0/0.8] Positive error in [a/Fe]log(Sun)stat.error;stat.maxfloatlogAge5[6.6/10.2] Log of age derived from the Lick absorption-line index fitted with the GALEV models (11)yrtime.agefloate_logAge5[0/0.315] Negative error in logAge5yrstat.errorfloatE_logAge5[0/0.85] Positive error in logAge5yrstat.error;stat.maxfloat[Fe/H]6[-2.2/0.24] Metallicity derived from the Lick absorption-line index fitted with the GALEV models (11)log(Sun)phys.abund.Zfloate_[Fe/H]6[0.075/0.76] Negative error in [Fe/H]log(Sun)stat.error;phys.abund.FefloatE_[Fe/H]6[0.001/1.5] Positive error in [Fe/H]log(Sun)stat.error;stat.maxfloatLickDisplay the Lick/IDS index fit results using four models (table7)meta.numberintnullableP10Display the data of the globular cluster selected from Peacock et al. 2010 (Cat. J/MNRAS/402/803)meta.ref.urlcharRBCDisplay the data from the Revised Bologna Catalog (RBC) v.5. (Galleti et al. 2012, Cat. V/143)meta.ref.urlcharJ/AJ/152/208/table7Lick/IDS index {chi}_min_^2^ fit results using Bruzual & Charlot 2003MNRAS.344.1000B modelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIMFInitial Mass Function (C=Chabrier, or S=Salpeter) (1)meta.codecharSETStellar Evolutionary Tracks (P00 or P94) (2)meta.codecharNameGlobular cluster identificationmeta.id;meta.maincharlogAge6[6.4/10.1] Lick/IDS log of age (3)yrtime.agefloate_logAge6[0.02/0.45] Negative error in logAge6yrstat.errorfloatE_logAge6[0.024/0.44] Positive error in logAge6yrstat.error;stat.maxfloat[Fe/H]7[-2.25/0.28] Lick/IDS metallicity (3)log(Sun)phys.abund.Fefloate_[Fe/H]7[0/0.5] Negative error in [Fe/H]7log(Sun)stat.error;phys.abund.FefloatE_[Fe/H]7[0.048/0.55] Positive error in [Fe/H]7log(Sun)stat.error;stat.maxfloatlogAge7[8.9/10.2] SED log of age (4)yrtime.agefloate_logAge7[0.004/0.62] Negative error in logAge7yrstat.errorfloatE_logAge7[0/0.63] Positive error in logAge7yrstat.error;stat.maxfloat[Fe/H]8[-2.25/0.56] SED metallicity (4)log(Sun)phys.abund.Fefloate_[Fe/H]8[0/0.74] Negative error in [Fe/H]8log(Sun)stat.error;phys.abund.FefloatE_[Fe/H]8[0/0.86] Positive error in [Fe/H]8log(Sun)stat.error;stat.maxfloatlogAge8[6.6/10.14] Log of age from both fits (5)yrtime.agefloate_logAge8[0.01/0.7] Negative error in logAge8yrstat.errorfloatE_logAge8[0/3.5] Positive error in logAge8yrstat.error;stat.maxfloat[Fe/H]9[-2.25/-0.17] Metallicity from both fits (5)log(Sun)phys.abund.Fefloate_[Fe/H]9[0/0.57] Negative error in [Fe/H]9log(Sun)stat.error;phys.abund.FefloatE_[Fe/H]9[0.06/0.73] Positive error in [Fe/H]9log(Sun)stat.error;stat.maxfloat