J/A+A/642/A168ivo://CDS.VizieR/J/A+A/642/A168doi:10.26093/cds/vizier.36420168CDSBerlanas S.R.Herrero A.Comeron F.Simon-Diaz S.Lennon D.J.,Pasquali A.Maiz Apellaniz J.Sota A.Pellerin A.2022-10-04T14:15:15Z2020-10-15T12:34:49ZCDS support team

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

cds-question@unistra.fro-starsspectroscopystellar-associationshertzsprung-russell-diagramCygnus OB2 provides a unique insight into the high-mass stellar content in one of the largest groups of young massive stars in our Galaxy. Although several studies of its massive population have been carried out over the last decades, an extensive spectroscopic study of the whole known O-star population in the association is still lacking. In this work, we created the most complete spectroscopic census of O stars carried out so far in Cygnus OB2 using already existing and new spectroscopy. We present the spectra for 78 O-type stars, from which we identify new binary systems, obtain the distribution of rotational velocities, and determine the main stellar parameters for all the stars in the region that have not been detected as double-line spectroscopic binaries. We also derive radii, luminosities, and masses for those stars with reliable Gaia astrometry, in addition to creating the Hertzsprung- Russell Diagram to interpret the evolutionary status of the association. This work has shown the improvement reached when using accurate spectroscopic parameters and astrometry for the interpretation of the evolutionary status of a population, revealing, in the case of Cygnus OB2, at least two star-forming bursts at ~3 and ~5Myr. We find an apparent deficit of very fast rotators in the distribution of rotational velocities. The inspection of the dynamical distribution of the sample has allowed us to identify nine O stars with peculiar proper motions and discuss a possible dynamical ejection scenario or past supernova explosions in the region.2020A&A...642A.168Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/642/A168CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/543/A101 : OB stars in Cygnus OB2 association (Comeron+, 2012)J/ApJ/643/238 : Chandra/2MASS sources in Cygnus OB2 (Butt+, 2006)J/ApJS/202/19 : riz photometry in Cyg OB2 (Guarcello+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/642/A168https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/642/A168http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/642/A168https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/642/A168https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/642/A168http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/642/A168GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/642/A168/tablea1 (Basic photometric data of the currently known O-type population of Cygnus OB2)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/642/A168/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/642/A168/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/642/A168/tablea1?GETtext/xml+votable180.050000true306.851166741.26272780.0055555555555555565/3673 6/14670-14671 14689 146918.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/642/A168?format=asciidefaultJ/A+A/642/A168/tablea1Basic photometric data of the currently known O-type population of Cygnus OB2SimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/78] Star identificationmeta.idintName? Common object namemeta.idchar2MASS2MASS object name, JHHMMSSss+DDMMSSsmeta.idcharRAJ2000Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainVmag? V magnitudemagphot.mag;em.opt.Vfloatnullabler_Vmag? V magnitude reference (1)meta.ref;pos.frameintnullableBmagB magnitude (2)magphot.mag;em.opt.Bfloatn_Bmag[*] Note on Bmag (2)meta.notecharJmag2MASS J magnitudemagphot.mag;em.IR.JfloatKsmag? 2MASS Ks magnitudemagphot.mag;em.IR.KfloatnullableJ/A+A/642/A168/tablea2Spectral classification and spectral data used for our O-starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/78] Star identificationmeta.idintName? Common object namemeta.idchar2MASS2MASS object name, JHHMMSSss+DDMMSSsmeta.idcharSpTypePPrevious spectral typesrc.spTypecharCom? Comments (2)meta.notecharDataA? Sources for broadening measurement (3)meta.bibcharDataB? Sources for spectroscopic analysis (3)meta.bibcharr_SpTypeP? Spectral type reference (1)meta.ref;pos.frameintnullableSpType? New spectral type (this work)src.spTypecharJ/A+A/642/A168/tablea3Spectroscopic stellar parameters and rotational velocities of the final O-type samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/78] Object identificationmeta.idintSpTypeSpectral typesrc.spTypecharTeffEffective temperaturekKphys.temperature.effectivefloate_TeffEffective temperature errorkKstat.error;phys.temperature.effectivefloatl_loggLimit flag on loggmeta.code.errorcharloggSurface gravitylog(cm.s**-2)phys.gravitychare_logg? Surface gravity errorlog(cm.s**-2)stat.errorcharl_mlogQLimit flag on mlogQmeta.code.errorcharmlogQOpposit of Wind-strength parameter (-logQ)stat.fit.paramchare_mlogQ? Wind-strength parameter errorstat.errorcharl_YheLimit flag on Yhemeta.code.errorcharYheHelium abundancephys.abund.Ychare_Yhe? Helium abundance errorstat.errorintnullablevsiniProjected rotational velocity (1)km/sphys.veloc.rotatintJ/A+A/642/A168/tablea4Fundamental parameters for the O-type sample with reliable Gaia astrometry (RUWE<1.4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/78] Object identificationmeta.idintGaiaDR2Gaia object source identificationmeta.iddDistance (1)pcpos.distanceintE_dPositive error on distance (1)pcstat.error;stat.maxinte_dNegative error on distance (1)pcstat.errorintAvVisual extinction (2)magphys.absorptionfloatVMAGAbsolute visual magnitude (2)magphys.magAbsfloate_VMAGAbsolute visual magnitude negative error (2)magstat.errorfloatE_VMAGAbsolute visual magnitude positive error (2)magstat.error;stat.maxfloatgroupMembership group (3)meta.code.member;pos.lgintRRadiuslog(solRad)phys.size.radiusfloatE_RRadius positive errorlog(solRad)stat.error;stat.maxfloate_RRadius negative errorlog(solRad)stat.errorfloatlogLLuminositylog(solLum)phys.luminosityfloatE_logLLuminosity positive errorlog(solLum)stat.error;stat.maxfloate_logLLuminosity negative errorlog(solLum)stat.errorfloatMspSpectroscopic masslog(solMass)phys.massfloatE_MspSpectroscopic mass positive errorlog(solMass)stat.error;stat.maxfloate_MspSpectroscopic mass negative errorlog(solMass)stat.errorfloat