J/ApJ/936/154ivo://CDS.VizieR/J/ApJ/936/154doi:10.26093/cds/vizier.19360154CDSWatkins L.L.van der Marel R.P.Libralato M.Bellini A.Anderson J.,Alfaro-Cuello M.2024-11-06T20:27:13Z2024-08-06T09:28:02ZCDS support team

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

cds-question@unistra.frglobular-star-clustersstellar-massesvisible-astronomyWe examine the degree of energy equipartition in nine Galactic globular clusters using proper motions measured with the Hubble Space Telescope. For most clusters in the sample, this is the first energy equipartition study ever performed. This study is also the largest of its kind, albeit with only nine clusters. We begin by rigorously cleaning the catalogs to remove poor-quality measurements and to ensure high signal to noise for the study. Using the cleaned catalogs, we investigate how velocity dispersion {sigma} changes with stellar mass m. We fit two functional forms: the first, a classic power law of the form {sigma}{prop}m-{eta} where {eta} is the degree of energy equipartition, and the second from Bianchini et al. parameterized by an equipartition mass meq where {eta} changes with stellar mass. We find that both functions fit well but cannot distinguish with statistical significance which function provides the best fit. All clusters exhibit varying degrees of partial equipartition; no cluster is at or near full equipartition. We search for correlations of {eta} and meq with various cluster properties. The most significant correlation is observed with the number of core or median relaxation times (N_core_ or Nhalf) the cluster has experienced. Finally, we determine the radial equipartition profile for each cluster, that is, how the degree of equipartition changes with projected distance from the cluster center. We do not detect statistically significant trends in the degree of equipartition with radius. Overall, our observational findings are in broad agreement with theoretical predictions from N-body models published in recent years.2022ApJ...936..154Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/936/154CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/195 : Globular Clusters in the Milky Way (Harris, 1996)VII/202 : Globular Clusters in the Milky Way (Harris, 1997)J/ApJ/710/1032 : Proper motions in {omega} Cen (Anderson+, 2010)J/ApJ/797/115 : HSTPROMO I. Observations and NGC7078 results (Bellini+, 2014)J/MNRAS/444/392 : Synthetic Stellar Photometry. I. (Casagrande+, 2014)J/ApJ/803/29 : HSTPROMO catalogs. II. Kinematic profiles (Watkins+, 2015)J/ApJ/812/149 : HSTPROMO. III. Dynamical distances (Watkins+, 2015)J/ApJ/827/12 : HSTPROMO cat of GCs IV. Blue straggler stars (Baldwin+, 2016)J/ApJ/853/86 : HST large programme on {omega} Centauri. II. (Bellini+, 2018)J/ApJ/861/99 : HSTPROMO cat. VI. Improved analysis NGC362 (Libralato+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/936/154https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/936/154http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/936/154https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/936/154https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/936/154http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/936/154GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/936/154/table2 (Binned velocity dispersion profiles as a function of stellar mass)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/936/154/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/936/154/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/936/154/table2?GETtext/xml+votable180.050000true6.0223292-72.08144440.0055555555555555560/https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/936/154?format=asciiOpticaldefaultJ/ApJ/936/154/table2Binned velocity dispersion profiles as a function of stellar massrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCluster namemeta.id;meta.maincharBin[1/10] bin numberem.binintNstar[224/7982] number of stars in binmeta.numberintMass[0.28/0.86] average stellar mass in binsolMassphys.mass;stat.meandoublee_Mass[0.003/0.07] spread in MasssolMassstat.error;phys.massdoublesigma[0.17/0.73] velocity dispersion in binmas/yrphys.veloc.dispersiondoublee_sigma[0.004/0.03] uncertainty on sigmamas/yrstat.errordoubleSimbadSimbad column added by the CDSmeta.ref.urlchar_RA<podition from Simbad (right ascension part)degpos.eq.ra;meta.main_DE<podition from Simbad (declination part)degpos.eq.dec;meta.main