J/A+A/627/A85ivo://CDS.VizieR/J/A+A/627/A85doi:10.26093/cds/vizier.36270085CDSZhang C.-P.Csengeri T.Wyrowski F.Li G.-X.Pillai T.Menten K.M.,Hatchell J.Thompson M.A.Pestalozz M.R.2019-09-16T11:08:18Z2019-07-04T08:04:14ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinterferometryradio-sourcesmillimeter-astronomysubmillimeter-astronomyMassive clumps tend to fragment into clusters of cores and condensations, some of which form high-mass stars. In this work, we study the structure of massive clumps at different scales, analyze the fragmentation process, and investigate the possibility that star formation is triggered by nearby HII regions. We present a high angular resolution study of a sample of 8 massive proto-cluster clumps. Combining infrared data, we use few-arcsecond resolution radio- and millimeter interferometric data to study their fragmentation and evolution. Our sample is unique in the sense that all the clumps have neighboring HII regions. Taking advantage of that, we test triggered star formation using a novel method where we study the alignment of the centres of mass traced by dust emission at multiple scales. The eight massive clumps have masses ranging from 228 to 2279M_{sun}_. The brightest compact structures within infrared bright clumps are typically associated with embedded compact radio continuum sources. The smaller scale structures of Reff~0.02pc observed within each clump are mostly gravitationally bound and massive enough to form at least a B3-B0 type star. Many condensations have masses larger than 8M_{sun}_ at small scale of Reff~0.02pc. Although the clumps are mostly infrared quiet, the dynamical movements are active at clump scale (~1pc). We studied the spatial distribution of the gas conditions detected at different scales. For some sources we find hints of external triggering, whereas for others we find no significant pattern that indicates triggering is dynamically unimportant. This probably indicates that the different clumps go through different evolutionary paths. In this respect, studies with larger samples are highly desired.2019A&A...627A..85Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/627/A85CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/627/A85https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/627/A85http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/627/A85https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/627/A85https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/627/A85http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/627/A85GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/627/A85/table1 (Parameters of PdBI observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/627/A85/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/627/A85/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/627/A85/table1?GETtext/xml+votable180.050000true276.28139167-13.242430560.005555555555555556Cone search capability for table J/A+A/627/A85/table2 (Parameters of VLA NH_3_ (1,1) observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/627/A85/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/627/A85/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/627/A85/table2?GETtext/xml+votable180.050000true276.28139167-13.242430560.005555555555555556Cone search capability for table J/A+A/627/A85/list (List of fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/627/A85/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/627/A85/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/627/A85/list?GETtext/xml+votable180.050000true276.28136-13.242470.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/627/A856/29505 29533 29535 302192.837779945223663e-21 4.414320678087048e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/627/A85?format=asciiRadioMillimeterdefaultJ/A+A/627/A85/table1Parameters of PdBI observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintConfConfiguration observation (CD or BCD)meta.notecharSourceSource namemeta.id;meta.maincharATLASGALATLASGAL name (GLLL.llll+B.bbbb)meta.idcharRAJ2000Phase center right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Phase center declination (J2000)pos.eq.dec;meta.main3.5beama3.5mm beam major axisarcsecphys.angSize;srcfloat3.5beamb3.5mm beam minor axisarcsecphys.angSize;srcfloat3.5beamPA3.5mm beam position angledegpos.posAng;instr.beamfloat3.5rms3.5mm rmsmJy/beaminstr.det.noisefloat1.3beama1.3mm beam major axisarcsecphys.angSize;srcfloat1.3beamb1.3mm beam minor axisarcsecphys.angSize;srcfloat1.3beamPA1.3mm beam position angledegpos.posAng;instr.beamfloat1.3rms1.3mm rmsmJy/beaminstr.det.noisefloatObs.dateObservation datestime.epochcharJ/A+A/627/A85/table2Parameters of VLA NH_3_ (1,1) observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintConfConfiguration observation (D)meta.notecharSourceSource namemeta.id;meta.maincharRAJ2000Phase center right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Phase center declination (J2000)pos.eq.dec;meta.mainNH3beamaVLA NH_3_ (1,1) beam major axisarcsecphys.angSize;srcfloatNH3beambVLA NH_3_ (1,1) beam minor axisarcsecphys.angSize;srcfloatNH3beamPAVLA NH_3_ (1,1) beam position angledegpos.posAng;instr.beamfloatNH3rmsVLA NH_3_ (1,1) rmsmJy/beaminstr.det.noisefloatJ/A+A/627/A85/table3The properties of infrared datan_IR[d] Note (3)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource namemeta.id;meta.maincharn_Source[ul] Note on Source (1)meta.notecharS4.5um? Flux density at 4.5ummJyphot.mag;em.IR.4-8umfloatnullablee_S4.5um? rms uncertainty on flux density at 4.5ummJystat.errorfloatnullableS8.0um? Flux density at 8.0ummJyphot.flux.density;em.IR.8-15umfloatnullablee_S8.0um? rms uncertainty on flux density at 8.0ummJystat.errorfloatnullableS24um? Flux density at 24ummJyphot.flux.density;em.IR.15-30umfloatnullablee_S24um? rms uncertainty on flux density at 24ummJystat.errorfloatnullableS70um? Flux density at 70ummJyphot.flux.density;em.IR.30-60umfloatnullablee_S70um? rms uncertainty on flux density at 70ummJystat.errorfloatnullableIRInfrared (bright or quiet) (2)meta.codecharHII[yes/no ] HII region ? (4)meta.codecharn_HII[d] Note (3)meta.notecharDistDistancekpcpos.distancefloatr_DistReference(s) for distance (5)meta.ref;pos.framecharJ/A+A/627/A85/table4Clump parameters derived from 450, 850, and 870micron observationsTkinKinematical temperatureKphys.temperaturefloate_Tkinrms uncertainty on kinematical temperatureKstat.errorfloatIpeakPeak intensity at BandJy/beamphot.fluxfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBandObserved band (450um, 850um, 870um, 1.3mm or 3.5mm)uminstr.bandpasscharConf[CD BCD] Configuration observationmeta.notecharSourceSource namemeta.id;meta.maincharNoClump or fragment sequential number within the Sourcemeta.numberintn_No[ab] Note on No (1)meta.notecharOffRAOffset in right ascensionarcsecpos.eq.ra;arith.difffloatOffDEOffset in declinationarcsecpos.eq.dec;arith.difffloatFWHMFWHMarcsecspect.line.widthfloatReffEffective radiuspcphys.size.radiusfloatSintIntegrated intensity at BandJyphot.flux.densityfloatCdust? Dust contribution (only in table 5)%stat.fit.paramfloatnullableMassMasssolMassphys.massfloate_Massrms uncertainty on masssolMassstat.error;phys.massfloatNH2H2 column density1e+23cm**-2phys.columnDensityfloate_NH2rms uncertainty on H2 column density1e+23cm**-2stat.error;phys.columnDensityfloatSigmaMass surface density {SIGMA}g.cm**-2phys.densityfloate_Sigmarms uncertainty on Sigmag.cm**-2stat.errorfloatnH2H2 density number100000cm**-3meta.number;phys.densityfloate_nH2rms uncertainty on H2 density number100000cm**-3stat.errorfloatDVNH3NH_3_ line widthkm/sspect.line.widthfloate_DVNH3rms uncertainty on DVNH3km/sstat.errorfloatMvirViral masssolMassphys.massfloate_Mvirrms uncertainty on Viral masssolMassstat.errorfloatJ/A+A/627/A85/table5Fragment parameters derived from PdBI 3.5mm observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBandObserved band (450um, 850um, 870um, 1.3mm or 3.5mm)uminstr.bandpasscharConf[CD BCD] Configuration observationmeta.notecharSourceSource namemeta.id;meta.maincharNoClump or fragment sequential number within the Sourcemeta.numberintn_No[ab] Note on No (1)meta.notecharOffRAOffset in right ascensionarcsecpos.eq.ra;arith.difffloatOffDEOffset in declinationarcsecpos.eq.dec;arith.difffloatFWHMFWHMarcsecspect.line.widthfloatReffEffective radiuspcphys.size.radiusfloatTkinKinematical temperatureKphys.temperaturefloate_Tkinrms uncertainty on kinematical temperatureKstat.errorfloatIpeakPeak intensity at BandJy/beamphot.fluxfloatSintIntegrated intensity at BandJyphot.flux.densityfloatCdust? Dust contribution (only in table 5)%stat.fit.paramfloatnullableMassMasssolMassphys.massfloate_Massrms uncertainty on masssolMassstat.error;phys.massfloatNH2H2 column density1e+23cm**-2phys.columnDensityfloate_NH2rms uncertainty on H2 column density1e+23cm**-2stat.error;phys.columnDensityfloatSigmaMass surface density {SIGMA}g.cm**-2phys.densityfloate_Sigmarms uncertainty on Sigmag.cm**-2stat.errorfloatnH2H2 density number100000cm**-3meta.number;phys.densityfloate_nH2rms uncertainty on H2 density number100000cm**-3stat.errorfloatDVNH3NH_3_ line widthkm/sspect.line.widthfloate_DVNH3rms uncertainty on DVNH3km/sstat.errorfloatMvirViral masssolMassphys.massfloate_Mvirrms uncertainty on Viral masssolMassstat.errorfloatJ/A+A/627/A85/table6Fragment parameters derived from PdBI 1.3mm observationsSigmaMass surface density {SIGMA}g.cm**-2phys.densityfloate_Sigmarms uncertainty on Sigmag.cm**-2stat.errorfloatnH2H2 density number100000cm**-3meta.number;phys.densityfloate_nH2rms uncertainty on H2 density number100000cm**-3stat.errorfloatCdust? Dust contribution (only in table 5)%stat.fit.paramfloatnullablen_No[ab] Note on No (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBandObserved band (450um, 850um, 870um, 1.3mm or 3.5mm)uminstr.bandpasscharConf[CD BCD] Configuration observationmeta.notecharSourceSource namemeta.id;meta.maincharNoClump or fragment sequential number within the Sourcemeta.numberintOffRAOffset in right ascensionarcsecpos.eq.ra;arith.difffloatOffDEOffset in declinationarcsecpos.eq.dec;arith.difffloatFWHMFWHMarcsecspect.line.widthfloatReffEffective radiuspcphys.size.radiusfloatTkinKinematical temperatureKphys.temperaturefloate_Tkinrms uncertainty on kinematical temperatureKstat.errorfloatIpeakPeak intensity at BandJy/beamphot.fluxfloatSintIntegrated intensity at BandJyphot.flux.densityfloatMassMasssolMassphys.massfloate_Massrms uncertainty on masssolMassstat.error;phys.massfloatNH2H2 column density1e+23cm**-2phys.columnDensityfloate_NH2rms uncertainty on H2 column density1e+23cm**-2stat.error;phys.columnDensityfloatDVNH3NH_3_ line widthkm/sspect.line.widthfloate_DVNH3rms uncertainty on DVNH3km/sstat.errorfloatMvirViral masssolMassphys.massfloate_Mvirrms uncertainty on Viral masssolMassstat.errorfloatJ/A+A/627/A85/listList of fits filesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharSourceSource namemeta.id;meta.maincharTitleTitle of the FITS filemeta.title;meta.fitscharAssocDataAssociated Data web pagemeta.ref.urlchar