J/ApJ/779/L6ivo://CDS.VizieR/J/ApJ/779/L6doi:10.26093/cds/vizier.17799006CDSDo T.Martinez G.D.Yelda S.Ghez A.Bullock J.Kaplinghat M.,Lu J.R.Peter A.H.G.Phifer K.2018-07-09T08:06:30Z2015-06-15T12:08:25ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyparallaxspectroscopyinfrared-photometryradial-velocityWe present three-dimensional (3D) kinematic observations of stars within the central 0.5pc of the Milky Way (MW) nuclear star cluster (NSC) using adaptive optics imaging and spectroscopy from the Keck telescopes. Recent observations have shown that the cluster has a shallower surface density profile than expected for a dynamically relaxed cusp, leading to important implications for its formation and evolution. However, the true 3D profile of the cluster is unknown due to the difficulty in de-projecting the stellar number counts. Here, we use spherical Jeans modeling of individual proper motions and radial velocities to constrain, for the first time, the de-projected spatial density profile, cluster velocity anisotropy, black hole mass (M_BH_), and distance to the Galactic center (R_0_) simultaneously. We find that the inner stellar density profile of the late-type stars, {rho}(r){prop.to}r^-{gamma}^, have a power law slope {gamma}=0.05_-0.60^+0.29^, much more shallow than the frequently assumed Bahcall-Wolf slope of {gamma}=7/4. The measured slope will significantly affect dynamical predictions involving the cluster, such as the dynamical friction time scale. The cluster core must be larger than 0.5 pc, which disfavors some scenarios for its origin. Our measurement of M_BH_=5.76_-1.26_^+1.76^x10^6^M_{sun}_ and R_0_=8.92_-0.55_^+0.58^kpc is consistent with that derived from stellar orbits within 1" of Sgr A*. When combined with the orbit of S0-2, the uncertainty on R_0_ is reduced by 30% (8.46_-0.38_^+0.42^kpc). We suggest that the MW NSC can be used in the future in combination with stellar orbits to significantly improve constraints on R_0_.2013ApJ...779L...6Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/779/L6CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/764/154 : Stellar populations in the central 0.5pc. I. (Do+, 2013)J/ApJ/725/331 : Astrometry in the Galactic Center (Yelda+, 2010)J/A+A/511/A18 : NIR observations of stars near SgrA* (Schoedel+, 2010)J/ApJ/703/1323 : Star spectroscopy in the Galaxy's nuclear cluster (Do+ 2009)J/A+A/502/91 : Proper motions of stars near SgrA* (Schoedel+, 2009)J/A+A/499/483 : NIR obs. of sources in galactic center (Buchholz+, 2009)J/ApJ/699/186 : VLA observations of the Galactic center (Zhao+, 2009)J/ApJ/681/1254 : Radial velocities of stars in the Galactic Center (Zhu+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/779/L6https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/779/L6http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/779/L6https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/779/L6https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/779/L6http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/779/L6GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/779/L6/table1 (Measured stellar positions and velocities)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/779/L6/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/779/L6/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/779/L6/table1?GETtext/xml+votable180.050000true266.41682972-29.007825280.0055555555555555566/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/779/L6?format=asciiInfrareddefaultJ/ApJ/779/L6/table1Measured stellar positions and velocitiesSimbadNameSimbad column added by the CDSmeta.idcharNameStellar identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKmag[9.6/16.3] The K' band magnitudemagphot.mag;em.IR.KfloatoRAOffset in Right Ascension (1)arcsecpos.eq.ra;arith.difffloatoDEOffset in Declination (1)arcsecpos.eq.dec;arith.difffloatxplx[-8.9/15.3] Parallax in the x directionmas/yrpos.parallaxfloate_xplx[0.02/0.8] Uncertainty in xplxmas/yrpos.parallaxfloatyplx[-13.5/24.2] Parallax in the y directionmas/yrpos.parallaxfloate_yplx[0.02/1] Uncertainty in yplxmas/yrpos.parallaxfloatEpochEpoch of the parallax observationsyrtime.epochdoubleRV[-738/597] Radial velocitykm/sphys.veloc;pos.heliocentricinte_RV[1/100] Statistical uncertainty in RV (2)km/sstat.errorintEp.RV[2005.5/2010.6] Epoch of the RV observationyrtime.epochdoubleDoDisplay data from Do+ 2013, J/ApJ/764/154 and Do+, 2009, J/ApJ/703/1323, if anymeta.ref.urlintnullable_RARight ascension added by the CDSdegpos.eq.ra;meta.main_DEDeclination added by the CDSdegpos.eq.dec;meta.main