J/ApJ/783/131ivo://CDS.VizieR/J/ApJ/783/131doi:10.26093/cds/vizier.17830131CDSYelda S.Ghez A.M.Lu J.R.Do T.Meyer L.Morris M.R.Matthews K.2017-07-03T14:26:51Z2016-05-04T12:55:11ZCDS support team

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

cds-question@unistra.frmilky-way-galaxystellar-associationsradial-velocityproper-motionsastrometrystandard-starsWe present new kinematic measurements and modeling of a sample of 116 young stars in the central parsec of the Galaxy in order to investigate the properties of the young stellar disk. The measurements were derived from a combination of speckle and laser guide star adaptive optics imaging and integral field spectroscopy from the Keck telescopes. Compared to earlier disk studies, the most important kinematic measurement improvement is in the precision of the accelerations in the plane of the sky, which have a factor of six smaller uncertainties ({sigma}~10{mu}as/yr2). We have also added the first radial velocity measurements for eight young stars, increasing the sample at the largest radii (6''-12'') by 25%. We derive the ensemble properties of the observed stars using Monte Carlo simulations of mock data. There is one highly significant kinematic feature (~20{sigma}), corresponding to the well-known clockwise disk, and no significant feature is detected at the location of the previously claimed counterclockwise disk. The true disk fraction is estimated to be ~20%, a factor of ~2.5 lower than previous claims, suggesting that we may be observing the remnant of what used to be a more densely populated stellar disk. The similarity in the kinematic properties of the B stars and the O/WR stars suggests a common star formation event. The intrinsic eccentricity distribution of the disk stars is unimodal, with an average value of <e> =0.27+/-0.07, which we show can be achieved through dynamical relaxation in an initially circular disk with a moderately top-heavy mass function.2014ApJ...783..131Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/783/131CatalogResearchIsServedByTAP 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/502/91 : Proper motions of stars near SgrA* (Schoedel+, 2009)J/A+A/499/483 : NIR observations of sources in GC (Buchholz+, 2009)J/ApJ/703/1323 : Spectroscopy of stars in Galaxy's nuclear cluster (Do+ 2009)J/ApJ/697/1741 : Warped disks of YSOs in Galactic center (Bartko+, 2009)J/ApJ/659/1241 : Stellar variability in Galactic Center (Rafelski+, 2007)J/ApJ/643/1011 : Early-type stars in the center of the Galaxy (Paumard+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/783/131https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/783/131http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/783/131https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/783/131https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/783/131http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/783/131GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/783/131/table8 (Galactic center secondary infrared astrometric standards)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/783/131/table8?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/783/131/table8?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/783/131/table8?GETtext/xml+votable180.050000true266.41692306-29.0077917780.005555555555555556Cone search capability for table J/ApJ/783/131/stars (Kinematic data and disk membership of Galactic center young stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/783/131/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/783/131/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/783/131/stars?GETtext/xml+votable180.050000true266.416930016-29.0075783060.0055555555555555566/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/783/131?format=asciiOpticaldefaultJ/ApJ/783/131/table8Galactic center secondary infrared astrometric standardspmDE[-9.7/9.7] Declination proper motion v_Decl_mas/yrpos.pm;pos.eq.decfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifier (1)meta.id;meta.maincharY10Display the measurements from Yelda et al. 2010 (cat. J/ApJ/725/331) compared with our updated astrometrymeta.ref.urlcharVelSimbad column added by the CDSmeta.ref.urlcharKpmag[7.4/16.3] K' band magnitudemagphot.mag;em.IR.KfloatEpIR[2006.53/2009.52] Average time of infrared positional measurements (T_0,IR_)yrtime.epochfloatRad[0.36/18.7] Radius from Sgr A*arcsecphys.angSize;srcfloatoRA[-6.6/15.6] Offset in Right Ascension from Sgr A* ({Delta}RA) (2)arcsecpos.eq.ra;arith.difffloate_oRA[1/2.2] Uncertainty in oRA ({sigma}_RA_) (3)masstat.errorfloatoDE[-9.6/12.4] Offset in Declination from Sgr A* ({Delta}_Decl_) (2)arcsecpos.eq.dec;arith.difffloate_oDE[1/2.2] Uncertainty in oDE ({sigma}_Decl_) (3)masstat.errorfloatpmRA[-9.5/9.5] Right Ascension proper motion v_RA_mas/yrpos.pm;pos.eq.rafloate_pmRA[0.1/1.4] Uncertainty in pmRA (4)mas/yrstat.error;pos.pm;pos.eq.rafloate_pmDE[0.2/1.5] Uncertainty in pmDE (4)mas/yrstat.error;pos.pm;pos.eq.decfloat_RACoordinates computed from oRA and oDE with Sgr A* SIMBAD position at 17:45:40.03599-29:00:28.1699 (right ascension part)degpos.eq.ra;meta.main_DECoordinates computed from oRA and oDE with Sgr A* SIMBAD position at 17:45:40.03599-29:00:28.1699 (declination part)degpos.eq.dec;meta.mainJ/ApJ/783/131/starsKinematic data and disk membership of Galactic center young starsr_RVReference for RV (4)meta.ref;pos.framecharNameStar namemeta.id;meta.maincharNe[3/45] Number of epochsmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGroupCategory of star based on the information content contained in the acceleration measurement (Det, Const, or LMS) (1)meta.idcharStdSimbad column added by the CDSmeta.ref.urlcharKmag[9.1/15.9] The K-band magnitudemagphot.mag;em.IR.KfloatEpoch[2001.3/2010.2] Epoch (2)yrtime.epochfloatoRA[-9.7/11.9] Offset in Right Ascension {Delta}RAarcsecpos.eq.ra;arith.difffloate_oRA[0.038/0.85] 1{sigma} error in oRAmasstat.errorfloatoDE[-8.2/11.7] Offset in Declination {Delta}Declarcsecpos.eq.dec;arith.difffloate_oDE[0.044/1.4] 1{sigma} error in oDEmasstat.errorfloatpmRA[-13.7/13.1] Right Ascension proper motion v_RA_mas/yrpos.pm;pos.eq.rafloate_pmRA[0.02/0.56] 1{sigma} error in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-10.9/9.7] Proper motion in Declination v_Decl_mas/yrpos.pm;pos.eq.decfloate_pmDE[0.02/0.74] 1{sigma} error in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatRV[-597/536] Radial velocity v_z_ (3)km/sphys.veloc;pos.heliocentricinte_RV[6/150] 1{sigma} error in RVkm/sstat.errorintDoDisplay the data from Do et al. 2009 (cat. J/ApJ/703/1323) and 2013 (cat. J/ApJ/764/154)meta.numberintnullableP06Display the data from Paumard et al. 2006 (cat. J/ApJ/643/1011) within 1.5''meta.ref.urlintnullableB09Display the data from Bartko et al. 2009 (cat. J/ApJ/697/1741) within 1.5''meta.ref.urlintnullablel_ddpm[>] Lower limit flag on ddpmmeta.code.errorcharddpm[-0.3/-0.02]? Radial acceleration a_R_ (5)mas.yr**-2spect.dopplerVelocfloatnullablee_ddpm[0.007/0.015]? 1{sigma} error in ddpmmas.yr**-2stat.errorfloatnullableProb[0/1] Disk membership probability calculated following Lu et al. (2009ApJ...690.1463L) (1-L_non-disk_) (6)stat.probability;meta.modelledfloatoPA[1/90] Position angle offset from the line of nodes of the clockwise disk ({Omega}=96.3{deg}), with a range of 0{deg}-90{deg}degpos.posAng;arith.difffloatSampleThe level above which the star's disk membership probability falls for its respective angular offset bin (see Figure 22)meta.idSimbadSimbad column added by the CDSmeta.ref.urlchar_RACoordinates computed from oRA and oDE with Sgr A* SIMBAD position at 17:45:40.03599-29:00:28.1699 (right ascension part)degpos.eq.ra;meta.main_DECoordinates computed from oRA and oDE with Sgr A* SIMBAD position at 17:45:40.03599-29:00:28.1699 (declination part)degpos.eq.dec;meta.main