J/ApJ/803/63ivo://CDS.VizieR/J/ApJ/803/63doi:10.26093/cds/vizier.18030063CDSKim D.Jerjen H.Milone A.P.Mackey D.Da Costa G.S.2017-09-19T14:21:00Z2015-10-06T16:11:57ZCDS support team

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

cds-question@unistra.frglobular-star-clustersmilky-way-galaxyinfrared-photometryvisible-astronomybroad-band-photometryWe report the discovery of a new, low-luminosity star cluster in the outer halo of the Milky Way. High-quality gr photometry is presented, from which a color-magnitude diagram is constructed, and estimates of age, [Fe/H], [{alpha}/Fe], and distance are derived. The star cluster, which we designate as Kim 2, lies at a heliocentric distance of ~105kpc. With a half-light radius of ~12.8pc and ellipticity of {epsilon}~0.12, it shares the properties of outer halo globular clusters, except for at higher metallicity ([Fe/H]~-1.0) and lower luminosity (M_v_~-1.5). These parameters are similar to those for the globular cluster AM 4, which is considered to be associated with the Sagittarius dwarf spheroidal galaxy. We find evidence of dynamical mass segregation and the presence of extra-tidal stars that suggests that Kim 2 is most likely a star cluster. Spectroscopic observations for radial-velocity membership and chemical abundance measurements are needed to further understand the nature of the object.2015ApJ...803...63Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/803/63CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/eso : ESO Science Archive Catalog (ESO, 1991-2015)VII/202 : Globular Clusters in the Milky Way (Harris, 1997)J/MNRAS/435/1928 : Dwarf galaxy planes in Local Group (Pawlowski+, 2013)J/ApJ/527/199 : HST observations of old clusters in the LMC (Johnson+, 1999)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/803/63https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/803/63http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/803/63https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/803/63https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/803/63http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/803/63GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/803/63/table4 (Properties of Kim 2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/803/63/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/803/63/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/803/63/table4?GETtext/xml+votable180.050000true317.2082083-51.16350.005555555555555556Cone search capability for table J/ApJ/803/63/table3 (GMOS photometry for stars within 3r_h_ from the center of Kim 2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/803/63/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/803/63/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/803/63/table3?GETtext/xml+votable180.050000true317.2075417-51.16296110.0055555555555555566/46021https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/803/63?format=asciiOpticalInfrareddefaultJ/ApJ/803/63/table4Properties of Kim 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCluster namemeta.id;meta.maincharRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latfloat(m-M)0Distance modulusmagphot.mag.distModfloate_(m-M)0Distance modulus uncertaintymagstat.errorfloatDist[104.7] Heliocentric distancekpcpos.distancefloate_DistHeliocentric distance uncertaintykpcstat.errorfloatDgc[99.4] Galactocentric distancekpcpos.distancefloate_DgcGalactocentric distance uncertaintykpcstat.errorfloat[Fe/H][-1] Metallicitylog(Sun)phys.abund.ZfloatE_[Fe/H]Positive error on [Fe/H]log(Sun)stat.error;stat.maxfloate_[Fe/H]Negative error on [Fe/H]log(Sun)stat.error;phys.abund.Fefloat[a/Fe][0.2] Abundance [{alpha}/Fe]log(Sun)phys.abundfloatAge[11.5] AgeGyrtime.agefloatE_AgePositive error on AgeGyrstat.error;stat.maxfloate_AgeNegative error on AgeGyrstat.error;time.agefloatrh[12.8] Half-light radius (Plummer profile) (1)pcphys.size.radiusfloate_rhrh uncertaintypcstat.errorfloatrc[8.5] Core radius (King profile) (1)pcphys.size.radiusfloate_rcrc uncertaintypcstat.errorfloatrtTidal radius (King profile) (1)pcphys.size.radiusfloate_rt[64] rt uncertaintypcstat.errorfloatell[0.12] Ellipticitysrc.ellipticityfloate_ellell uncertaintystat.errorfloatPA[35] Position Angle ({theta})degpos.posAnginte_PAPA uncertaintydegstat.errorintMv[-1.5] Total V-band luminositymagphot.mag;em.optfloate_MvM_V_ uncertaintymagstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/803/63/table3GMOS photometry for stars within 3r_h_ from the center of Kim 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainDist[0.04/1.3] Radial distancearcminphys.angSizefloatrmag[20.4/26.5] GMOS r-band magnitudemagphot.mag;em.opt.Rfloatg-r[-0.2/1.9] GMOS g-r color indexmagphot.color;em.opt.B;em.opt.Rfloat