J/ApJ/805/160ivo://CDS.VizieR/J/ApJ/805/160doi:10.26093/cds/vizier.18050160CDSSimanton L.A.Chandar R.Whitmore B.C.2017-01-23T22:00:00Z2015-10-20T13:26:19ZCDS support team

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

cds-question@unistra.frgalaxiesglobular-star-clustershst-photometryWe present a new photometric catalog of 326 candidate globular clusters (GCs) in the nearby spiral galaxy M101, selected from B, V, and I Hubble Space Telescope Advanced Camera for Surveys images. The luminosity function (LF) of these clusters has an unusually large number of faint sources compared with GCLFs in many other spiral galaxies. Accordingly, we separate and compare the properties of "bright" (M_v_<-6.5) versus "faint" (M_v_>-6.5; one magnitude fainter than the expected GC peak) clusters within our sample. The LF of the bright clusters is well fit by a peaked distribution similar to those observed in the Milky Way (MW) and other galaxies. These bright clusters also have similar size (r_eff_) and spatial distributions as MW GCs. The LF of the faint clusters, on the other hand, is well described by a power law, dN(L_v_)/dL_v_{propto}L_v_^{alpha}^ with {alpha}=2.6+/-0.3, similar to those observed for young and intermediate-age cluster systems in star forming galaxies. We find that the faint clusters have larger typical r_eff_ than the bright clusters, and have a flatter surface density profile, being more evenly distributed, as we would expect for clusters associated with the disk. We use the shape of the LF and predictions for mass-loss driven by two-body relaxation to constrain the ages of the faint clusters. Our results are consistent with two populations of old star clusters in M101: a bright population of halo clusters and a fainter, possibly younger, population of old disk clusters.2015ApJ...805..160Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/805/160CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/146/114 : Massive stars in M101. I. HST BVI photometry (Grammer+, 2013)J/AJ/143/52 : Old star clusters in NGC 4449 from HST (Strader+, 2012)J/ApJ/733/124 : Cepheids in M101 observed with HST (Shappee+, 2011)J/MNRAS/403/429 : Candidate globular clusters in NGC 5170 (Forbes+, 2010)J/A+A/507/1375 : HST/ACS VI data of M31 globular clusters (Perina+, 2009)J/MNRAS/343/665 : VI photometry of globular cluster systems (Goudfrooij+, 2003)J/A+AS/139/393 : Young Massive Star Clusters. II. (Larsen, 1999)J/ApJS/122/431 : Star Clusters in M33 (Chandar+, 1999)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/805/160https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/805/160http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/805/160https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/805/160https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/805/160http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/805/160GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/805/160/table1 (M101 old star cluster catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/805/160/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/805/160/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/805/160/table1?GETtext/xml+votable180.050000true210.819554.32723330.0055555555555555566/11434https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/805/160?format=asciiOpticaldefaultJ/ApJ/805/160/table1M101 old star cluster catalogB-V[0.5/1.5] The HST/ACS (B-V) color indexmagphot.color;em.opt.B;em.opt.VfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[945/271453] Identification Numbermeta.id;meta.mainintRAJ2000[14] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[54] Degree of Declination (J2000)pos.eq.dec;meta.mainVMag[-9.5/-5.1] Absolute V band magnitudemagphys.magAbs;em.opt.VfloatV-I[0.8/2.1] The HST/ACS (V-I) color indexmagphot.color;em.opt.V;em.opt.IfloatB-I[1.3/3.4] The HST/ACS (B-I) color indexmagphot.color;em.opt.B;em.opt.RfloatRad[0.7/15.2]? Effective radius (1)pcphys.size.radiusfloatnullable