J/A+A/417/115ivo://CDS.VizieR/J/A+A/417/115doi:10.26093/cds/vizier.34170115CDSWilliams S.J.Fuller G.A.Sridharan T.K.2007-11-06T11:48:25Z2007-11-06T12:41:37ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsinterstellar-mediuminfrared-sourcesWe present maps of the 850{mu}m and 450{mu}m continuum emission seen towards a sample of 68 high-mass protostellar candidates with luminosities ranging from 10^2.5^L_{sun}_ to ~10^5^L_{sun}_. Most of these candidate high-mass stars are in the earliest stages of evolution, and have not yet developed an ultra-compact HII region. We observe a variety of continuum emission morphologies, from compact symmetric sources through to multiple cores embedded in long filaments of emission. We find on average there is a 65% probability of an IRAS point-source having a companion detection at submillimetre wavelengths. The ratio of integrated flux to peak flux for our detections shows no strong dependence on distance, suggesting the emission we have observed is primarily from scale-free envelopes with power-law density structures. Assuming a near kinematic distance projection, the clumps we detect vary in mass from ~1M_{sun}_ to over 1000M_{sun}_, with a mean clump mass of 330M_{sun}_, column density of 9x10^23cm^-2^ and diameter of ~0.6pc. The high luminosity and low mass of the smallest clumps suggests they are accompanied by a minimal number of stellar companions, while the most massive clumps may be examples of young protogroups and protoclusters. We measure the spectral index of the dust emission ({alpha}) and the spectral index of the dust grain opacity ({beta}) towards each object, finding clumps with morphologies suggestive of strong temperature gradients, and of grain growth in their dense inner regions. We find a mean value for beta of 0.9, significantly smaller than observed towards ultra-compact HII regions.2004A&A...417..115Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/417/115CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/417/115https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/417/115http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/417/115https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/417/115https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/417/115http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/417/115GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/417/115/table2 (Position and flux of submm detections)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/417/115/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/417/115/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/417/115/table2?GETtext/xml+votable180.050000true84.79535.7544440.0055555555555555566/13049 13051 14287 14306-14307 14309 14333 14353 14409 14625 14655 14670 14689-14690 14693 14697 15629 15683 23795 24378 24554 29100-29101 29103 29118 29461 29505 29509 29511 29513 29529 29532 30218-30219 30241 30244-30245 30259-30260 30262 30268-30269 30312-30313 30319 30330 30405 30419-30420 30594-30595 30605 30691 30695 30714 30716 30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/417/115?format=asciiInfrareddefaultJ/A+A/417/115/table2Position and flux of submm detectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWFSSource identifiermeta.id;meta.mainintIRASAssociated IRAS point source (<II/125>)meta.idcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainP850um? Peak 850{mu}m flux, in Jy/beamJyphot.flux.density;em.mm.200-400GHzfloatnullablee_P850um? 1-sigma uncertainty in P850um, in Jy/beamJystat.errorfloatnullableI850um? Integrated 850{mu}m fluxJyphot.flux.density;em.mm.200-400GHzfloatnullablee_I850um? 1-sigma uncertainty in I850umJystat.errorfloatnullableP450um? Peak 450{mu}m flux, in Jy/beamJyphot.flux.density;em.mm.400-750GHzfloatnullablee_P450um? 1-sigma uncertainty in P450um, in Jy/beamJystat.errorfloatnullableI450um? Integrated 450{mu}m fluxJyphot.flux.density;em.mm.400-750GHzfloatnullablee_I450um? 1-sigma uncertainty in I450umJystat.errorfloatnullableY? Ratio of integrated/peak flux at 850{mu}mphot.flux;arith.ratiofloatnullableNote[1/2]? Problematic detections (1)meta.noteintnullable