J/ApJ/813/42ivo://CDS.VizieR/J/ApJ/813/42doi:10.26093/cds/vizier.18130042CDSKiminki M.M.Kim J.S.Bagley M.B.Sherry W.H.Rieke G.H.2017-09-12T11:49:28Z2016-03-14T17:01:04ZCDS support team

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

cds-question@unistra.frearly-type-starsinfrared-photometryvisible-astronomyphotometryspectroscopystellar-spectral-typesastronomical-object-identificationWe present the first results from our survey of the star-forming complex W3, combining VRI photometry with multiobject spectroscopy to identify and characterize the high-mass stellar population across the region. With 79 new spectral classifications, we bring the total number of spectroscopically confirmed O- and B-type stars in W3 to 105. We find that the high-mass slope of the mass function in W3 is consistent with a Salpeter IMF, and that the extinction toward the region is best characterized by an R_V_ of approximately 3.6. B-type stars are found to be more widely dispersed across the W3 giant molecular cloud (GMC) than previously realized: they are not confined to the high-density layer (HDL) created by the expansion of the neighboring W4 H ii region into the GMC. This broader B-type population suggests that star formation in W3 began spontaneously up to 8-10 Myr ago, although at a lower level than the more recent star formation episodes in the HDL. In addition, we describe a method of optimizing sky subtraction for fiber spectra in regions of strong and spatially variable nebular emission.2015ApJ...813...42Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/813/42CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)III/195 : Atlas of Optical Spectral Classification OB Stars (Walborn+ 1990)J/A+A/561/A12 : W3 Main JHKs photometry (Bik+, 2014)J/ApJS/213/34 : Velocities of Cygnus OB2 massive binaries (Kobulnicky+, 2014)J/ApJS/213/1 : The MSFRs Omnibus X-ray Catalog (MOXC) (Townsley+, 2014)J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)J/ApJ/751/4 : Radial velocities of massive stars in Cyg OB2 (Kiminki+, 2012)J/ApJ/743/39 : Spitzer obs. of W3 molecular cloud (Rivera-Ingraham+, 2011)J/ApJS/196/18 : CO survey of galactic molecular clouds. II. (Bieging+, 2011)J/ApJ/733/113 : IRAC observations of IC 1795 (Roccatagliata+, 2011)J/ApJS/194/9 : X-ray star clusters in the Carina complex (Feigelson+, 2011)J/ApJ/654/338 : Spitzer photometry in W3 molecular cloud (Ruch+, 2007)J/A+A/457/637 : UBVJHK synthetic photom. of Galactic O stars (Martins+, 2006)J/AJ/129/907 : New Ori OB1 members (Briceno+, 2005)J/AJ/129/393 : UBV photometry in W3 (Oey+, 2005)J/ApJ/454/151 : OB Associations of the Northern Milky Way (Massey+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/813/42https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/813/42http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/813/42https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/813/42https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/813/42http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/813/42GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/813/42/table2 (Photometry and spectral types of candidate O- and B-type stars in W3)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/813/42/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/813/42/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/813/42/table2?GETtext/xml+votable180.050000true35.665166762.19805560.0055555555555555566/3648 3649 36512.2537631428488926e-19 3.9395800315085955e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/813/42?format=asciiInfraredOpticaldefaultJ/ApJ/813/42/table2Photometry and spectral types of candidate O- and B-type stars in W3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqIdentification number from this workmeta.id;meta.mainintRAJ2000[2] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[61/62] Degree of Declination (J2000)pos.eq.dec;meta.main2MASS2MASS based IAU Name (JHHMMSSss+DDMMSSs)meta.id.crosscharAltIDAlternative identification (1)meta.idcharVmag[13.9/20.3]? Cousins/Bessell V magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag[0.03/0.09]? Uncertainty in Vmagmagstat.error;phot.mag;em.opt.VfloatnullableRmag[13.2/18]? Cousins/Bessell R magnitudemagphot.mag;em.opt.Rfloatnullablee_Rmag[0.03/0.05]? Uncertainty in Rmagmagstat.error;phot.mag;em.opt.RfloatnullableImag[12.4/16]? Cousins/Bessell I magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag[0.03]? Uncertainty in Imagmagstat.error;phot.mag;em.opt.IfloatnullableAv[2.4/12.2]? Magnitudes of extinction in V for R_V_=3.6magphys.absorptionfloatnullablee_Av[0/0.6]? Uncertainty in Avmagstat.errorfloatnullableSpTSpectroscopic classification (2)src.spTypecharf_SpTComments on spectral properties (3)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlchar