J/ApJ/706/727ivo://CDS.VizieR/J/ApJ/706/727doi:10.26093/cds/vizier.17060727CDSMarshall D.J.Joncas G.Jones A.P.2026-05-19T14:25:37Z2010-03-28T16:18:50ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinfrared-sourcesgalaxy-classification-systemsInfrared Dark Clouds (IRDCs) are dark clouds seen in silhouette in mid-infrared surveys. They are thought to be the birthplace of massive stars, yet remarkably little information exists on the properties of the population as a whole (e.g., mass spectrum, spatial distribution). Genetic forward modeling is used along with the Two Micron All Sky Survey and the Besancon Galactic model to deduce the three-dimensional distribution of interstellar extinction toward previously identified IRDC candidates. This derived dust distribution can then be used to determine the distance and mass of IRDCs, independently of kinematic models of the Milky Way. Along a line of sight that crosses an IRDC, the extinction is seen to rise sharply at the distance of the cloud. Assuming a dust-to-gas ratio, the total mass of the cloud can be estimated. The method has been successfully applied to 1259 IRDCs, including over 1000 for which no distance or mass estimate currently exists. The IRDCs are seen to lie preferentially along the spiral arms and in the molecular ring of the Milky Way, reinforcing the idea that they are the birthplace of massive stars. Also, their mass spectrum is seen to follow a power law with an index of -1.75+/-0.06, steeper than giant molecular clouds (GMCs) in the inner Galaxy but comparable to clumps in GMCs. This slope suggests that the IRDCs detected using the present method are not gravitationally bound, but are rather the result of density fluctuations induced by turbulence.2009ApJ...706..727Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/706/727CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)J/ApJS/95/457 : IRAS images of nearby dark clouds (Wood+ 1994)J/ApJS/166/567 : Radio Molecular lines in infrared dark clouds (Ragan+, 2006)J/ApJ/653/1325 : Galactic distribution of infrared dark clouds (Simon+, 2006)J/ApJ/651/L125 : Water masers associated with IR dark cloud cores (Wang+ 2006)J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)J/ApJ/639/227 : MSX IRDC candidate catalog (Simon+, 2006)J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)J/A+A/499/149 : 1.2mm maps of southern Infrared Dark Clouds (Vasyunina+ 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/706/727https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/706/727http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/706/727https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/706/727https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/706/727http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/706/727GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/706/727/irdc (Results for the Infra-Red Dark Cloud (IRDC) characteristics (table1 of the paper))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/706/727/irdc?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/706/727/irdc?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/706/727/irdc?GETtext/xml+votable180.050000true266.628443-28.899580.0055555555555555565/7202-7203 7206-7207 7228-7229 7275 7278 7377 7383 7564 10420 10453 10543 10553 10556 10594-10595 10598 10612 10614-10615 10624 6/14665-14667 14670 14682-14683 14690 14693 14697 14704 28803 28806 28817-28818 28852-28853 28874-28875 28878 28890-28891 28896-28897 28900-28901 28925 29088 29090-29091 29094-29097 29116 29118-29119 29162-29163 29456-29457 29460-29461 29463 29469 29504-29506 29512-29513 29516-29517 29522-29523 29526 29528-29529 30216 30218-30219 30222 30240-30241 30244-30245 30247 30260 30262-30263 30265 30268-30269 30312-30313 30315 30318-30319 30405 30416-30417 30420-30421 30605 30644 30692 30694 30712 37343 37899 37928 38017-38018 41599 41653-41655 41661 41671 41676 41678 41684-41685 41688-41689 41696 41698 41767-41768 41770 41772-41773 41776 41809 41811 41817 41820 42155 42158-42159 42167 42169-42171 42203 42206-42207 42210-42211 42216-42217 42220 42228-42229 42387 42390-42391 42396-42398 42400 42417 42433 42435 42437-42441 42444-42445 42447 42454-42455 42500-42501 42512 42516 43019https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/706/727?format=asciiOpticalInfrareddefaultJ/ApJ/706/727/irdcResults for the Infra-Red Dark Cloud (IRDC) characteristics (table1 of the paper)DistDistance to IRDCkpcpos.distance;pos.heliocentricfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMSXDCIRDC Name (GLLL.ll+BB.bbb) (1)meta.id;meta.maincharGlonGalactic Longitudedegpos.galactic.lonGlatGalactic Latitudedegpos.galactic.latAKsKs band extinction of IRDCmagphys.absorptionfloatSizeSize of IRDCpcphys.size.diameterfloatMassMass of IRDCsolMassphys.massintNobsNumber of 2MASS stars used in calculationmeta.numberintchi2rReduced chi squared of J-K histogram fit (2)stat.fit.chi2floatsigmaStandard deviation above diffuse extinctionstat.stdevfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed