J/A+A/559/A79ivo://CDS.VizieR/J/A+A/559/A79doi:10.26093/cds/vizier.35590079CDSRagan S.E.Henning T.Beuther H.2014-04-22T08:03:45Z2014-04-07T13:23:49ZCDS support team

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

cds-question@unistra.frinfrared-sourcesmolecular-cloudsmillimeter-astronomysubmillimeter-astronomyInfrared-dark clouds (IRDCs) harbor the early phases of cluster and high-mass star formation and are comprised of cold (~20K), dense (n>10^4^cm^-3^) gas. The spectral energy distribution (SED) of IRDCs is dominated by the far-infrared and millimeter wavelength regime, and our initial Herschel study examined IRDCs at the peak of the SED with high angular resolution. Here we present a follow-up study using the SABOCA instrument on APEX which delivers 7.8" angular resolution at 350{mu}m, matching the resolution we achieved with Herschel/PACS, and allowing us to characterize substructure on ~0.1pc scales. Our sample of 11 nearby IRDCs are a mix of filamentary and clumpy morphologies, and the filamentary clouds show significant hierarchical structure, while the clumpy IRDCs exhibit little hierarchical structure. All IRDCs, regardless of morphology, have about 14% of their total mass in small scale core-like structures which roughly follow a trend of constant volume density over all size scales. Out of the 89 protostellar cores we identified in this sample with Herschel, we recover 40 of the brightest and re-fit their SEDs and find their properties agree fairly well with our previous estimates (<T>~19K). We detect a new population of "cold cores" which have no 70{mu}m counterpart, but are 100 and 160{mu}m-bright, with colder temperatures (<T>~16K). This latter population, along with SABOCA-only detections, are predominantly low-mass objects, but their evolutionary diagnostics are consistent with the earliest starless or prestellar phase of cores in IRDCs.2013A&A...559A..79Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/559/A79CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/706/727 : Distance and mass of Infrared Dark Clouds (Marshall+, 2009)J/A+A/547/A49 : Herschel EPoS: high-mass overview (Ragan+, 2012)J/A+A/561/A148 : Mass Distribution of Infrared Dark Clouds (Gomez+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/559/A79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/559/A79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/559/A79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/559/A79https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/559/A79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/559/A79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/559/A79/table1 (Target and observation summary)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/559/A79/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/559/A79/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/559/A79/table1?GETtext/xml+votable180.050000true209.020417-62.2283330.005555555555555556Cone search capability for table J/A+A/559/A79/tableb1 (Leaves from dendrogram decomposition of SABOCA 350um image)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/559/A79/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/559/A79/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/559/A79/tableb1?GETtext/xml+votable180.050000true209.005833-62.2388890.0055555555555555566/28900 29090 29097 29100 29118 29505 29510 30256 30258 41682 41772 41780 418025.675559809562688e-22 5.675559809562688e-22https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/559/A79?format=asciiInfraredRadiodefaultJ/A+A/559/A79/table1Target and observation summaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIRDCIRDC (Infra-Red Dark Cloud) name \linkRole{leaves data }meta.id;meta.maincharprimaryn_IRDC[*] *: filamentary IRDCsmeta.notecharNlNumber of "leaeves" for this structuremeta.numberintnullableRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainDist[2.3/5] Distancekpcpos.distance;pos.heliocentricfloatE_DistError on Dist (upper value)kpcstat.error;stat.maxfloate_DistError on Dist (lower value)kpcstat.errorfloatMassMass above N~10^21^cm-2 from ATLASGAL survey (see Ragan et al., 2012, Cat. J/A+A/547/A49)solMassmeta.ref;pos.frameintSize1Map sizearcsecphys.angSize;obs.fieldintSize2Map sizearcsecphys.angSize;obs.fieldintObsDateObservation datetime.epoch;obsnullableTint[3780/21000] Integration timestime.epochintrmsrms (in Jy/beam)Jyinstr.det.noisefloatNH2sensH2 column density sensitivitycm**-2phys.columnDensitydoubleJ/A+A/559/A79/tableb1Leaves from dendrogram decomposition of SABOCA 350um imageComCommentsmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIRDCIRDC name \linkRole{target and observation summary }meta.id;meta.maincharLeaf[1/42] Leaf number within the IRDCmeta.idintn_Leaf[c] Leaf overlaps multiple cores (1)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainStotIntegrated flux contribution from dendrogram leaf (with parent branch/trunk flux subtracted) at 350umJyphot.flux.density;em.mm.750-1500GHzfloatSparParent branch/trunk flux (in Jy/beam)Jyphot.flux.density;em.mm.750-1500GHzfloatNH2Mean H2 column density (2)cm**-2phys.columnDensity;stat.meandoubleReffEffective radiuspcphys.size.radiusfloatM20KMass calculated from 350um data with T(dust)=20KsolMassphys.massintMMass calculated from 350um datasolMassphys.mass;meta.modelledint