J/ApJ/726/18ivo://CDS.VizieR/J/ApJ/726/18doi:10.26093/cds/vizier.17260018CDSKoenig X.P.Allen L.E.2017-06-20T13:17:13Z2012-09-10T14:19:55ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomysloan-photometrystellar-spectral-typesa-starsyoung-stellar-objectsemission-line-starsWe present the results of a survey of young intermediate-mass stars (age<5Myr, 1.5M_{sun}_<M*<=15M_{sun}_) in the W5 massive star-forming region. We use combined optical, near-infrared, and Spitzer Space Telescope photometry and optical spectroscopy to define a sample of stars of spectral types A and B and examine their infrared excess properties. We find objects with infrared excesses characteristic of optically thick disks, i.e., Herbig AeBe stars. These stars are rare: <1.5% of the entire spectroscopic sample of A and B stars, and absent among stars more massive than 2.4M_{sun}_. 7.5% of the A and B stars possess infrared excesses in a variety of morphologies that suggest their disks are in some transitional phase between an initial, optically thick accretion state and later evolutionary states. We identify four morphological classes based on the wavelength dependence of the observed excess emission above theoretical photospheric levels: (1) the optically thick disks; (2) disks with an optically thin excess over the wavelength range 2-24um, similar to that shown by Classical Be stars; (3) disks that are optically thin in their inner regions based on their infrared excess at 2-8um and optically thick in their outer regions based on the magnitude of the observed excess emission at 24um; (4) disks that exhibit empty inner regions (no excess emission at {lambda}<8um) and some measurable excess emission at 24um. A sub-class of disks exhibit no significant excess emission at {lambda}<=5.8um, have excess emission only in the Spitzer 8um band and no detection at 24um. We discuss these spectral energy distribution types, and suggest physical models for disks exhibiting these emission patterns and additional observations to test these theories.2011ApJ...726...18Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/726/18CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/306 : The SDSS Photometric Catalog, Release 8 (Adelman-McCarthy+, 2011)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/MNRAS/415/1202 : BVI photometry in W5E HII region (Chauhan+, 2011)J/ApJ/688/1142 : Star formation in W5: Spitzer observations (Koenig+, 2008)J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/726/18https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/726/18http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/726/18https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/726/18https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/726/18http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/726/18GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/726/18/stars (W5 IR excess spectral catalog ; 27 duplicated stars of table1 also present in table2 have been removed)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/726/18/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/726/18/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/726/18/stars?GETtext/xml+votable180.050000true41.9226830660.521748060.0055555555555555565/825 6/3279 3290 33126.772611666688002e-21 3.5010283109654867e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/726/18?format=asciiOpticalInfrareddefaultJ/ApJ/726/18/starsW5 IR excess spectral catalog ; 27 duplicated stars of table1 also present in table2 have been removedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1141/20326] ID number from Koenig et al. 2008, Cat. J/ApJ/688/1142, <[KAG2008] NNNNN> in Simbadmeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainJmag[2/17]? 2MASS J band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? Uncertainty in Jmagcmagstat.error;phot.mag;em.IR.JintnullableHmag[2/17]? 2MASS H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Uncertainty in Hmagcmagstat.error;phot.mag;em.IR.HintnullableKsmag[2/19]? 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag? Uncertainty in Ksmagcmagstat.error;phot.mag;em.IR.Kintnullable[3.6][5/15] Spitzer/IRAC 3.6 micron band magnitudemagphot.mag;em.IR.3-4umfloate_[3.6]Uncertainty in [3.6]cmagstat.errorint[4.5][4/15] Spitzer/IRAC 4.5 micron band magnitudemagphot.mag;em.IR.4-8umfloate_[4.5]Uncertainty in [4.5]cmagstat.errorint[5.8][4/15]? Spitzer/IRAC 5.8 micron band magnitudemagphot.flux.density;em.IR.4-8umfloatnullablee_[5.8]? Uncertainty in [5.8]cmagstat.errorintnullable[8.0][3/14]? Spitzer/IRAC 8.0 micron band magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_[8.0]? Uncertainty in [8.0]cmagstat.errorintnullable[24][0.9/11]? Spitzer/MIPS 24 micron band magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_[24]? Uncertainty in [24]cmagstat.errorintnullabler'mag[9/22]? SDSS r' band magnitudemagphot.mag;em.opt.Rfloatnullablee_r'mag? Uncertainty in r'magcmagstat.error;phot.mag;em.opt.Rintnullablez'mag[8/20]? SDSS z' band magnitudemagphot.mag;em.opt.Ifloatnullablee_z'mag? Uncertainty in z'magcmagstat.error;phot.mag;em.opt.IintnullableSpTMK spectral type and subtype (only A or B for table 2)src.spTypechare_SpT[0.5/2] Uncertainty in spectral typestat.errorfloatEWHa? H{alpha} equivalent width; in Angstroms0.1nmspect.line.eqWidth;em.line.HalphafloatnullableAV[0.01/6.83]? V band extinctionmagphys.absorption;em.opt.Vfloatnullablee_AV? Uncertainty in AVcmagstat.errorintnullableDisk[a-e] Disk morphology from IR excess for A and B stars (2)src.classcharSEDSED plot of this starmeta.ref.urlchar2MDisplay the 2MASS data within 1.5" (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.refchar