J/ApJ/713/871ivo://CDS.VizieR/J/ApJ/713/871doi:10.26093/cds/vizier.17130871CDSWright N.J.Drake J.J.Drew J.E.Vink J.S.2012-06-04T21:24:45Z2012-05-14T13:38:05ZCDS support team

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

cds-question@unistra.frstellar-associationspre-main-sequence-starsstellar-massesyoung-stellar-objectsextinctionearly-type-starsCygnus OB2 is the nearest example of a massive star-forming region (SFR), containing over 50 O-type stars and hundreds of B-type stars. We have analyzed the properties of young stars in two fields in Cyg OB2 using the recently published deep catalog of Chandra X-ray point sources with complementary optical and near-IR photometry. Our sample is complete to ~1M_{sun}_ (excluding A- and B-type stars that do not emit X-rays), making this the deepest study of the stellar properties and star formation history in Cyg OB2 to date. Combining our stellar mass function (MF) and an estimate of the radial density profile of the association suggests a total mass of Cyg OB2 of ~3x10^4^M_{sun}_, similar to that of many of our Galaxy's most massive SFRs.2010ApJ...713..871Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/713/871CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/536/A31 : Cyg OB2 XMM observations (Rauw, 2011)J/ApJS/184/84 : X-ray sources in Cyg OB2 region (Wright+, 2009)J/A+A/486/453 : NIR photometry of early-type stars in Cyg OB2 (Comeron+, 2008)J/ApJ/664/1102 : Radial velocity survey of Cyg OB2 association (Kiminki+, 2007)J/A+A/464/211 : Chandra and near-IR obs. of Cyg OB2 (Albacete Colombo+, 2007)J/AJ/101/1408 : Massive stars in Cyg OB2. (Massey+ 1991)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/713/871https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/713/871http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/713/871https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/713/871https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/713/871http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/713/871GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/713/871/table1 (Derived stellar properties of sources in Cygnus OB2 with optical or near-IR associations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/713/871/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/713/871/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/713/871/table1?GETtext/xml+votable180.050000true307.816791741.44227780.0055555555555555566/14692 14693https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/713/871?format=asciidefaultJ/ApJ/713/871/table1Derived stellar properties of sources in Cygnus OB2 with optical or near-IR associationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[WD2009][1/1696] Running X-ray source numbermeta.id;meta.mainintRAJ2000Hour of Right Ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (1)pos.eq.dec;meta.mainMmb[N/Y] Association membership informationmeta.code.membercharMass? Stellar masssolMassphys.massfloatnullabler_MassMethod or reference for mass and extinction (2)meta.refcharAV? Extinction toward sourcemagphys.absorptionfloatnullable