J/ApJ/764/154ivo://CDS.VizieR/J/ApJ/764/154doi:10.26093/cds/vizier.17640154CDSDo T.Lu J.R.Ghez A.M.Morris M.R.Yelda S.Martinez G.D.,Wright S.A.Matthews K.2025-07-21T20:11:55Z2014-11-20T14:29:51ZCDS support team

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

cds-question@unistra.frmilky-way-galaxylate-type-starsearly-type-starsinfrared-astronomyspectroscopyWe present new high angular resolution near-infrared spectroscopic observations of the nuclear star cluster surrounding the Milky Way's central supermassive black hole. Using the integral-field spectrograph OSIRIS on Keck II behind the laser-guide-star adaptive optics system, this spectroscopic survey enables us to separate early-type (young, 4-6Myr) and late-type (old, >1Gyr) stars with a completeness of 50% down to K'=15.5mag, which corresponds to ~10M_{sun}_ for the early-type stars. This work increases the radial extent of reported OSIRIS/Keck measurements by more than a factor of three from 4" to 14" (0.16 to 0.56pc), along the projected disk of young stars. For our analysis, we implement a new method of completeness correction using a combination of star-planting simulations and Bayesian inference. We assign probabilities for the spectral type of every source detected in deep imaging down to K'=15.5mag using information from spectra, simulations, number counts, and the distribution of stars. The inferred radial surface-density profiles, {Sigma}(R){prop.to}R^-{Gamma}^, for the young stars and late-type giants are consistent with earlier results ({Gamma}_early_=0.93+/-0.09, {Gamma}_late_=0.16+/-0.07). The late-type surface-density profile is approximately flat out to the edge of the survey. While the late-type stellar luminosity function is consistent with the Galactic bulge, the completeness-corrected luminosity function of the early-type stars has significantly more young stars at faint magnitudes compared with previous surveys with similar depth. This luminosity function indicates that the corresponding mass function of the young stars is likely less top-heavy than that inferred from previous surveys.2013ApJ...764..154Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/764/154CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/737/73 : Infrared extinction toward the Galactic Centre (Fritz+, 2011)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/A+A/499/483 : NIR obs. of sources in galactic center (Buchholz+, 2009)J/ApJ/703/1323 : Spectro. of stars in the Galaxy's nuclear cluster (Do+ 2009)J/ApJ/697/1741 : Warped disks of YSOs in Galactic center (Bartko+, 2009)J/ApJ/643/1011 : Early-type stars in the center of the Galaxy (Paumard+, 2006)J/A+A/457/637 : UBVJHK synthetic phot. of Galactic O stars (Martins+, 2006)J/A+A/426/81 : Kinematic analysis of the Minispiral (Paumard+, 2004)J/ApJ/597/323 : Cool stars at the Galactic Center (Blum+, 2003)J/ApJS/107/281 : Atlas of hot, luminous stars at 2 microns (Hanson+ 1996)J/ApJ/470/864 : JHKL photometry of the Galactic Center (Blum+, 1996)J/AJ/110/2788 : JHK photometry for Galactic bulge stars (Tiede+ 1995)J/A+AS/97/587 : JHK photometry of Galactic center stars (Ruelas-Mayorga+ 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/764/154https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/764/154http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/764/154https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/764/154https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/764/154http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/764/154GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/764/154/stars (OSIRIS observations of late-type and early-type stars of the Galactic Central Cluster stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/764/154/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/764/154/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/764/154/stars?GETtext/xml+votable180.050000true266.41684694-29.007911110.0055555555555555566/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/764/154?format=asciiInfrareddefaultJ/ApJ/764/154/starsOSIRIS observations of late-type and early-type stars of the Galactic Central Cluster starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTSimbad column added by the CDSmeta.code.classcharNameStar name (SNN-NNN or IRSNNWW)meta.id;meta.maincharf_Name[d] Status changed from Do et al. 2009 (1)meta.codecharK'mag[9.5/16] K'-band magnitude (2)magphot.mag;em.IR.Kfloate_K'mag[0.01/0.4]? K'mag uncertaintymagstat.error;phot.mag;em.IR.KfloatnullableK'mag0[9.2/16] K'-band magnitude corrected for differential extinction (2)magphot.mag;em.IR.KfloatRAoffRight ascension offset from Sgr A*arcsecpos.eq.raDEoffDeclination offset from Sgr A*arcsecpos.eq.decRad[0.1/13.3] Projected radius (R)arcsecphys.size.radiusfloatEpoch[2003/2010] Epoch in decimal yearstime.epochfloatEW? Equivalent width of NaI (late-type stars) or of Br{gamma} (early-type stars)0.1nmspect.line.eqWidthfloatnullablee_EW? EW uncertainty0.1nmstat.error;spect.line.eqWidthfloatnullableNobs[1/24]? Number of observations (3)meta.numberintnullableS/N[5/149]? Signal to noise ratio (4)stat.snrintnullableFieldField designationmeta.idcharD09Link to data from Do+, 2009, J/ApJ/703/1323, if anymeta.numberintnullable_RASimbad column added by the CDSdegpos.eq.ra;meta.main_DESimbad column added by the CDSdegpos.eq.dec;meta.mainSimbadNameSimbad column added by the CDSmeta.idchar