J/ApJ/786/117ivo://CDS.VizieR/J/ApJ/786/117doi:10.26093/cds/vizier.17860117CDSFouesneau M.Johnson L.C.Weisz D.R.Dalcanton J.J.Bell E.F.,Bianchi L.Caldwell N.Gouliermis D.A.Guhathakurta P.Kalirai J.,Larsen S.S.Rix H.-W.Seth A.C.Skillman E.D.Williams B.F.2017-09-25T14:13:47Z2017-08-08T07:56:47ZCDS support team

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

cds-question@unistra.frgalaxiesglobular-star-clustersextinctionstellar-agesstellar-massesWe present ages and masses for 601 star clusters in M31 from the analysis of the six filter integrated light measurements from near-ultraviolet to near-infrared wavelengths, made as part of the Panchromatic Hubble Andromeda Treasury (PHAT). We derive the ages and masses using a probabilistic technique, which accounts for the effects of stochastic sampling of the stellar initial mass function. Tests on synthetic data show that this method, in conjunction with the exquisite sensitivity of the PHAT observations and their broad wavelength baseline, provides robust age and mass recovery for clusters ranging from ~10^2^ to 2x10^6^ M_{sun}_. We find that the cluster age distribution is consistent with being uniform over the past 100 Myr, which suggests a weak effect of cluster disruption within M31. The age distribution of older (>100 Myr) clusters falls toward old ages, consistent with a power-law decline of index -1, likely from a combination of fading and disruption of the clusters. We find that the mass distribution of the whole sample can be well described by a single power law with a spectral index of -1.9+/-0.1 over the range of 10^3^-3x10^5^ M_{sun}_. However, if we subdivide the sample by galactocentric radius, we find that the age distributions remain unchanged. However, the mass spectral index varies significantly, showing best-fit values between -2.2 and -1.8, with the shallower slope in the highest star formation intensity regions. We explore the robustness of our study to potential systematics and conclude that the cluster mass function may vary with respect to environment.2014ApJ...786..117Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/786/117CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/449/143 : Photometry of M31 globular cluster candidates (Ma+, 2006)J/AJ/139/1438 : SED and age estimates of 104 M31 globular clustersJ/ApJ/752/95 : PHAT stellar cluster survey. I. Year 1 (Johnson+, 2012)J/A+A/549/A60 : Ages and [Fe/H] of M31 globular clusters (Cezario+, 2013)J/ApJ/762/123 : PHAT. IV. Initial Mass Function (Weisz+, 2013)J/ApJS/215/9 : PHAT X. UV-IR photometry of M31 stars (Williams+, 2014)J/ApJ/827/33 : PHAT. XVI. Star cluster masses and ages (Johnson+, 2016)J/A+A/602/A112 : M31 PHAT star clusters (de Meulenaer+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/786/117https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/786/117http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/786/117https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/786/117https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/786/117http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/786/117GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/786/117/table2 (Ag-Mass and extinction results from the analysis with discrete cluster models)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/786/117/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/786/117/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/786/117/table2?GETtext/xml+votable180.050000true11.638273629082942.19388652280910.0055555555555555566/2623 2666 2709 2752https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/786/117?format=asciidefaultJ/ApJ/786/117/table2Ag-Mass and extinction results from the analysis with discrete cluster modelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPCID[1/1728] PHAT identifier ([JSD2012] PC NNNN in Simbad) (1)meta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainAV-best? Best V band extinction (2)magphys.absorptionfloatnullableAV-p16? The 16th percentile V band extinctionmagphys.absorptionfloatnullableAV-p84? The 84th percentile V band extinctionmagphys.absorptionfloatnullableAV-p2.5? The 2.5th percentile V band extinctionmagphys.absorptionfloatnullableAV-p97.5? The 97.5th percentile V band extinctionmagphys.absorptionfloatnullablelogA-best? Best log age (2)log(yr)time.age;meta.modelledfloatnullablelogA-p16? The 16th percentile log agelog(yr)time.agefloatnullablelogA-p84? The 84th percentile log agelog(yr)time.agefloatnullablelogA-p2.5? The 2.5th percentile log agelog(yr)time.agefloatnullablelogA-p97.5? The 97.5th percentile log agelog(yr)time.agefloatnullablelogM-bset? Best log mass (2)log(solMass)phys.massfloatnullablelogM-p16? The 16th percentile masslog(solMass)phys.massfloatnullablelogM-p84? The 84th percentile masslog(solMass)phys.massfloatnullablelogM-p2.5? The 2.5th percentile masslog(solMass)phys.massfloatnullablelogM-p97.5? The 97.5th percentile masslog(solMass)phys.massfloatnullableCFlag[0/1]? Suspicious fit from visual color-magnitude inspection (3)meta.codeintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar