J/ApJ/715/310ivo://CDS.VizieR/J/ApJ/715/310doi:10.26093/cds/vizier.17150310CDSRathborne J.M.Jackson J.M.Chambers E.T.Stojimirovic I.Simon R.,Shipman R.Frieswijk W.2017-06-30T05:48:16Z2012-05-30T12:59:08ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinterstellar-mediuminfrared-sourcesmillimeter-astronomysubmillimeter-astronomyIdentified as extinction features against the bright Galactic mid-infrared background, infrared dark clouds (IRDCs) are thought to harbor the very earliest stages of star and cluster formation. In order to better characterize the properties of their embedded cores, we have obtained new 24um, 60-100um, and submillimeter continuum data toward a sample of 38 IRDCs. The 24um Spitzer images reveal that while the IRDCs remain dark, many of the cores are associated with bright 24um emission sources, which suggests that they contain one or more embedded protostars. Combining the 24um, 60-100um, and submillimeter continuum data, we have constructed broadband spectral energy distributions (SEDs) for 157 of the cores within these IRDCs and, using simple graybody fits to the SEDs, have estimated their dust temperatures, emissivities, opacities, bolometric luminosities, masses, and densities. Based on their Spitzer/Infrared Array Camera 3-8um colors and the presence of 24um point-source emission, we have separated cores that harbor active, high-mass star formation from cores that are quiescent. The active "protostellar" cores typically have warmer dust temperatures and higher bolometric luminosities than the more quiescent, perhaps "pre-protostellar," cores. Because the mass distributions of the populations are similar, however, we speculate that the active and quiescent cores may represent different evolutionary stages of the same underlying population of cores. Although we cannot rule out low-mass star formation in the quiescent cores, the most massive of them are excellent candidates for the "high-mass starless core" phase, the very earliest in the formation of a high-mass star.2010ApJ...715..310Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/715/310CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)J/ApJ/639/227 : MSX IRDC candidate catalog (Simon+, 2006)J/A+A/481/345 : SED evolution in massive YSOs (Molinari+, 2008)J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)J/ApJ/653/1325 : Galactic distribution of infrared dark clouds (Simon+, 2006)J/ApJ/651/L125 : Water masers associated with IRDC cores (Wang+, 2006)J/ApJ/639/227 : MSX IRDC candidate catalog (Simon+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/715/310https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/715/310http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/715/310https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/715/310https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/715/310http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/715/310GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/715/310/table2 (Core coordinates, distances, and measured fluxes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/715/310/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/715/310/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/715/310/table2?GETtext/xml+votable180.050000true274.46-15.8938890.0055555555555555566/29118 29508 29510 29529 29532 29533 29535 30218 30245 30256 30258 30262 30263 30315 30318 30319 30330 30417 30421 30692 307161.6553710550405622e-22 1.000830682546041e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/715/310?format=asciiInfraredRadiodefaultJ/ApJ/715/310/table2Core coordinates, distances, and measured fluxesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMSXDCThe IRDC core identification (GLLL.ll+DD.dd MMNN)meta.id;meta.maincharprimaryPSimbad column added by the CDSmeta.ref.urlcharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainDistDistancekpcpos.distance;pos.heliocentricfloatl_F24Limit flag on F24meta.code.errorcharF24Spitzer/MIPS 24 micron band flux densityJyphot.flux.density;em.IR.15-30umfloatF55? Spitzer 55um flux densityJyphot.flux.density;em.IR.30-60umfloatnullableF65? Spitzer 65um flux densityJyphot.flux.density;em.IR.30-60umfloatnullableF75? Spitzer 75um flux densityJyphot.flux.density;em.IR.30-60umfloatnullableF85? Spitzer 85um flux densityJyphot.flux.density;em.IR.60-100umfloatnullableF95? Spitzer 95um flux densityJyphot.flux.density;em.IR.60-100umfloatnullableF350? CSO 350um flux densityJyphot.flux.density;em.mm.750-1500GHzfloatnullableF450? CSO or JCMT 450um flux densityJyphot.flux;em.IRfloatnullableF850? JCMT 850um flux densityJyphot.flux.density;em.mm.200-400GHzfloatnullableSEDSimbad column added by the CDSmeta.ref.urlcharF1200IRAM 1.2mm flux densityJyphot.flux.density;em.mm.200-400GHzfloatR06Link to IRDC cores properties from Rathborne et al., 2006, Cat. J/ApJ/641/389meta.ref.urlcharSimbadSimbad column added by the CDSmeta.refcharJ/ApJ/715/310/table3Properties of the cores derived from gray-body fits to their broadband SEDsbetaDust emissivity indexstat.fit.paramfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMSXDCThe IRDC core identification (GLLL.ll+DD.dd MMNN)meta.id;meta.maincharTdustDust temperatureKphys.temperatureinttau250Optical depth at 250 micronsphys.absorption.opticalDepthfloatLumLuminositysolLumphys.luminosityintMassMasssolMassphys.massintlogNH2Log of the beam-average H_2_ column densitylog(cm**-2)phys.columnDensityfloatlognH2Log of the volume-average H_2_ densitylog(cm**-3)phys.densityfloatl_chi2Limit flag on chi2meta.code.errorcharchi2The {chi}^2^ of best fitstat.fit.chi2;meta.modelledfloatCl[ABIQR] Classification (G1)meta.code.classcharJ/ApJ/715/310/table4Properties of the cores for which limits where estimated from the gray-body fits to their broadband SEDsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMSXDCThe IRDC core identification (GLLL.ll+DD.dd MMNN)meta.id;meta.maincharb_TdustLower limit of dust temperatureKphys.temperature;stat.minintB_TdustUpper limit of dust temperatureKphys.temperature;stat.maxintb_tau250Lower limit of optical depth at 250 micronsphys.absorption.opticalDepth;stat.minfloatB_tau250Upper limit of optical depth at 250 micronsphys.absorption.opticalDepth;stat.maxfloatb_betaLower limit of dust emissivity indexmeta.code;spect.index;stat.minfloatB_betaUpper limit of dust emissivity indexmeta.code;spect.index;stat.maxfloatb_LumLower limit of luminositysolLumphys.luminosity;stat.minintB_LumUpper limit of luminositysolLumphys.luminosity;stat.maxintb_MassLower limit of masssolMassphys.mass;stat.minintB_MassUpper limit of masssolMassphys.mass;stat.maxintl_b_chi2Limit flag on b_chi2meta.code.errorcharb_chi2Lower limit of {chi}^2^ of best fitmeta.notefloatl_B_chi2Limit flag on B_chi2meta.code.errorcharB_chi2Upper limit of {chi}^2^ of best fitmeta.notefloatCl[BIQR] Source classification (G1)meta.code.classchar