J/ApJ/827/12ivo://CDS.VizieR/J/ApJ/827/12doi:10.26093/cds/vizier.18270012CDSBaldwin A.T.Watkins L.L.van der Marel R.P.Bianchini P.Bellini A.,Anderson J.2017-10-02T19:28:38Z2016-12-02T12:51:38ZCDS support team

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

cds-question@unistra.frglobular-star-clustersgalaxy-kinematicsstellar-massesmetallicityWe make use of the Hubble Space Telescope proper-motion catalogs derived by Bellini et al. (Paper I, 2014, J/ApJ/797/115) to produce the first radial velocity dispersion profiles {sigma}(R) for blue straggler stars (BSSs) in Galactic globular clusters (GCs), as well as the first dynamical estimates for the average mass of the entire BSS population. We show that BSSs typically have lower velocity dispersions than stars with mass equal to the main-sequence turnoff mass, as one would expect for a more massive population of stars. Since GCs are expected to experience some degree of energy equipartition, we use the relation {sigma}{propto}M^-{eta}^, where {eta} is related to the degree of energy equipartition, along with our velocity dispersion profiles to estimate BSS masses. We estimate {eta} as a function of cluster relaxation from recent Monte Carlo cluster simulations by Bianchini+ (2016MNRAS.458.3644B) and then derive an average mass ratio M_BSS_/M_MSTO_=1.50+/-0.14 and an average mass M_BSS_=1.22+/-0.12M_{sun}_ from 598 BSSs across 19 GCs. The final error bars include any systematic errors that are random between different clusters, but not any potential biases inherent to our methodology. Our results are in good agreement with the average mass of M_BSS_=1.22+/-0.06M_{sun}_ for the 35 BSSs in Galactic GCs in the literature with properties that have allowed individual mass determination.2016ApJ...827...12Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/827/12CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/202 : Globular Clusters in the Milky Way (Harris, 1997)J/ApJ/816/70 : Spectra of 3 NGC104 member stars (Ferraro+, 2016)J/ApJ/812/149 : HSTPROMO. III. Dynamical distances (Watkins+, 2015)J/ApJ/803/29 : HSTPROMO catalogs. II. Kinematic profiles (Watkins+, 2015)J/ApJ/801/67 : Grid of binary colors in M30 (NGC7099) (Xin+, 2015)J/ApJ/797/115 : HSTPROMO I. Observations and NGC7078 results (Bellini+, 2014)J/ApJ/754/91 : Abundances and velocities of NGC 6397 stars (Lovisi+, 2012)J/ApJ/732/108 : Abundances of 92 giants in Plaut's window (Johnson+, 2011)J/ApJ/710/1032 : Proper motions in {omega} Cen (Anderson+, 2010)J/AJ/137/3743 : Spectroscopic binary orbits in NGC 188 (Geller+, 2009)J/ApJ/682/1217 : Abundances in red giants in 7 globular clusters (Kirby+, 2008)J/ApJ/677/1069 : Blue stragglers in NGC 6388 (Dalessandro+, 2008)J/ApJ/663/267 : Blue straggler population of M5 (Lanzoni+, 2007)J/ApJS/166/249 : Stellar dynamics & proper motions in 47Tuc (McLaughlin+, 2006)J/ApJ/648/1026 : HST photometry of M5 blue stragglers (Warren+, 2006)J/ApJ/632/894 : Blue stragglers, HB & turnoff stars in 4 GC (De Marco+, 2005)J/ApJ/625/156 : FUV-NUV observations of NGC 2808 (Dieball+, 2005)J/A+A/324/915 : Blue stragglers in M3 (Ferraro+ 1997)J/AJ/108/1786 : Blue stragglers and variable stars in M3 (Guhathakurta+, 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/827/12https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/827/12http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/827/12https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/827/12https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/827/12http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/827/12GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/827/12/table3 (Properties and results for Galactic globular clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/827/12/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/827/12/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/827/12/table3?GETtext/xml+votable180.050000true6.0223292-72.08144440.0055555555555555566/9666 12405 16647 28705 28751 28973 31417 33321 33330 34242 37294 41304 41852 42076 42314 42841 43227 47125 47868https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/827/12?format=asciidefaultJ/ApJ/827/12/table3Properties and results for Galactic globular clustersE_fUpper error on fstat.error;stat.maxfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNrNumber of bin measurements for this clustermeta.numberintnullableNGCCluster namemeta.id;meta.mainintprimary[Fe/H][-2.4/-0.4] Metallicity (1)log(Sun)phys.abund.ZfloatTage[10.7/13] Cluster age (2)Gyrtime.agefloatcRad[1/143] Core radius (1)arcsecphys.angSize;srcfloatlogTrc[-4.1/0.6] Core relaxation time, log (1)log(Gyr)time.relaxfloatlognrel[0.5/5.2] Number of relaxation times, Tage/Trc, logmeta.numberfloatMeq[1.5/3.1] Equipartition mass (3)solMassphys.massfloateta[0.2/0.4] Equipartition parameter {eta}stat.fit.paramfloatMMSTO[0.7/0.9] Main-sequence turnoff (MSTO) masssolMassphys.massfloatalpha[0.6/1.2] Scale factor {alpha}, {alpha}=(MBSS/MMSTO)^-{eta}^arith.factorfloate_alpha[0.04/0.2] Uncertainty in alphastat.error;pos.eq.rafloatf[0.7/2.8] Average blue straggler star mass (MBSS) as a multiple of MMSTO, f=MBSS/MMSTOphys.mass;arith.ratiofloate_fLower error on fstat.errorfloatMBSS[0.5/2.2] Average blue straggler star (BSS) mass, in solar massessolMassphys.massfloatE_MBSSUpper error on MBSSsolMassstat.error;stat.maxfloate_MBSSLower error on MBSSsolMassstat.errorfloatpPapDisplay data from previous papers (Bellini+, 2014, J/ApJ/797/115; Watkins+, 2015, J/ApJ/803/29 and J/ApJ/812/149)meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharNEDSimbad 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/ApJ/827/12/table2Blue straggler radial dispersion profilesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNGCCluster namemeta.id;meta.mainintNBSS[6/14] Number of blue straggler stars in the binmeta.numberintRad[7/148] Mean radius of the binarcsecphys.angSize;srcdoublee_Rad[1/17] Uncertainty in Radarcsecphys.angSize;srcfloatsigma[0.04/0.9] Binned velocity dispersionmas/yrphys.veloc.dispersionfloate_sigma[0.01/0.2] Uncertainty in {sigma}mas/yrstat.errorfloat