J/ApJ/831/67ivo://CDS.VizieR/J/ApJ/831/67doi:10.26093/cds/vizier.18310067CDSBarnes P.J.Hernandez A.K.O'Dougherty S.N.Schap III W.J.Muller E.2019-12-03T11:05:59Z2017-02-27T10:22:30ZCDS support team

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

cds-question@unistra.frinterstellar-mediumradio-astronomygalaxy-kinematicsmolecular-cloudssurveysmillimeter-astronomysubmillimeter-astronomyWe report the second complete molecular line data release from the Census of High- and Medium-mass Protostars (CHaMP), a large-scale, unbiased, uniform mapping survey at sub-parsec resolution, of millimeter-wave line emission from 303 massive, dense molecular clumps in the Milky Way. This release is for all ^12^CO J=1->0 emission associated with the dense gas, the first from Phase II of the survey, which includes ^12^CO, ^13^CO, and C^18^O. The observed clump emission traced by both ^12^CO and HCO^+^ (from Phase I) shows very similar morphology, indicating that, for dense molecular clouds and complexes of all sizes, parsec-scale clumps contain {Xi}~75% of the mass, while only 25% of the mass lies in extended (>~10pc) or "low density" components in these same areas. The mass fraction of all gas above a density of 10^9^m^-3^ is {xi}_9_>~50%. This suggests that parsec-scale clumps may be the basic building blocks of the molecular interstellar medium, rather than the standard giant molecular cloud (GMC) concept. Using ^12^CO emission, we derive physical properties of these clumps in their entirety, and compare them to properties from HCO^+^, tracing their denser interiors. We compare the standard X-factor converting I_^12^CO_ to N_H2_ with alternative conversions, and show that only the latter give whole-clump properties that are physically consistent with those of their interiors. We infer that the clump population is systematically closer to virial equilibrium than when considering only their interiors, with perhaps half being long-lived (10s of Myr), pressure-confined entities that only terminally engage in vigorous massive star formation, supporting other evidence along these lines that was previously published.2016ApJ...831...67Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/831/67CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/780/173 : Masses of giant molecular clouds in Milky Way (Battisti+, 2014)J/ApJ/779/79 : Galactic CHaMP. II. Dense gas clumps. (Ma+, 2013)J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)J/ApJS/196/12 : First results from Mopra HCO^+^ maps (Barnes+, 2011)J/ApJ/723/492 : Properties of GRS molecular clouds (Roman-Duval+, 2010)http://www.astro.ufl.edu/~peterb/research/thrumms/ : Three-mm Ultimate Moprahttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/831/67https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/831/67http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/831/67https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/831/67https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/831/67http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/831/67GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/831/67/table1 (CHaMP clumps ^12^CO J=1->0 observed parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/831/67/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/831/67/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/831/67/table1?GETtext/xml+votable180.050000true148.46875-56.737110.0055555555555555565/9480 9504 6/37333 37335 37342 37343 37361 37363 37364 37366 37367 37368 37369 37371 37372 37373 37374 37894 37897 37899 37902 37924 37926 37930 38024 38025 43017 43019 43020 43041https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/831/67?format=asciiMillimeterRadiodefaultJ/ApJ/831/67/table1CHaMP clumps ^12^CO J=1->0 observed parametersl_amajLimit flag on amajmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBYFBYF number from Paper I (Barnes+, 2011, J/ApJS/196/12)meta.id;meta.mainintprimarym_BYFSubclump letter from Paper I (1)meta.code.multipcharGLONp? Galactic longitude, emission peakdegpos.galactic.lonnullableGLATp? Galactic latitude, emission peakdegpos.galactic.latnullableoposFlag on ^12^CO observation (2)meta.codecharI12CO[5/262]? ^12^CO J=1->0 integrated intensity, I(12CO)=integral(T*RdV)K.km/sphot.flux.density;em.IR.Jfloatnullablee_I12CO[0.2/2]? Uncertainty in I12COK.km/sstat.errorfloatnullablebVel[-45/3] Lower velocity range used for moment calculationskm/sinstr.bandwidthfloatBVel[-35/27] Upper velocity range used for moment calculationskm/sinstr.bandwidthfloatTp[4/34]? Peak brightness temperatureKphys.temperature;stat.maxfloatnullablee_Tp[0.4/1.1]? Uncertainty in TpKstat.errorfloatnullableVlsr[-41/20]? Intensity-weighted LSR velocitykm/sphys.veloc;pos.lsrfloatnullablee_Vlsr[0.06/1]? Uncertainty in Vlsrkm/sstat.error;phys.veloc;pos.lsrfloatnullableSigV[0.4/6.6]? Velocity dispersionkm/sphys.veloc.dispersionfloatnullablee_SigV[0.06/1]? Uncertainty in SigVkm/sstat.errorfloatnullableamaj[34/831]? Major axis size, 2D decompositionarcsecphys.angSizeintnullablee_amaj[12]? Uncertainty in amajarcsecstat.errorintnullablel_bminLimit flag on bminmeta.code.errorcharbmin[24/479]? Minor axis size, 2D decompositionarcsecphys.angSizeintnullablee_bmin[12/24]? Uncertainty in bminarcsecstat.errorintnullablePA? Position angle, 2D decompositiondegpos.posAngintnullablee_PA? Uncertainty in PAdegstat.errorintnullableeposFlag on 2D elliptical gaussian decomposition (2)meta.codecharGLONc? Galactic longitude, emission centroiddegpos.galactic.lonnullableGLATc? Galactic latitude, emission centroiddegpos.galactic.latfloatnullablePapIIDisplay the clump data from Paper II (Ma+, 2013, J/ApJ/779/79)meta.ref.urlintnullablePapIDisplay data from Paper I (Barnes+, 2011, J/ApJS/196/12)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexedJ/ApJ/831/67/table2CHaMP clumps ^12^CO J=1->0 physical parameters with standard N_H2_ conversionm_BYFSubclump letter from Paper Imeta.code.multipcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBYFBYF number from Paper I (Barnes+, 2011, J/ApJS/196/12)meta.id;meta.mainintDist[1/7] Final distance (1)kpcpos.distance;pos.heliocentricfloatf_DistFlag on Dist (2)meta.codecharNCOPeak column density in ^12^CO J=1->0m**-2phys.columnDensity;stat.maxdoubleSigp[17/3233] Mass surface densitysolMass.pc**-2phys.densityfloatRad[0.1/7.2] Clump radiuspcphys.size.radiusfloatrcolEquivalent mass densitysolMass.pc**-3phys.densitydoublencol[4/1264] Estimated density at the emission peakm**-3phys.densityfloatMcol[7/58792] LTE masssolMassphys.massintPgas[0.3/925] Implied central gas pressurepPaphys.pressure;em.wl.centralfloatLCO[2/4807] Peak line luminosity, ^12^CO J=1->0K.km.s**-1.pc**-2phys.luminositydoublealpha[0.3/209] Virial {alpha} parameter ({alpha}=Mvir/Mcol)phys.mass;arith.ratiofloatRJe[0.1/1.3] Rayleigh-Jeans radiuspcphys.size.radiusfloatMBE[52/232539] Bonnor-Ebert masssolMassphys.massintJ/ApJ/831/67/table3CHaMP clumps ^12^CO J=1->0 physical parameters with ThrUMMS N_H2_ conversionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBYFBYF number from Paper I (Barnes+, 2011, J/ApJS/196/12)meta.id;meta.mainintm_BYFSubclump letter from Paper Imeta.code.multipcharDist[1/7] Final distance (1)kpcpos.distance;pos.heliocentricfloatf_DistFlag on Dist (2)meta.codecharNCOPeak column density in ^12^CO J=1->0m**-2phys.columnDensity;stat.maxdoubleSigp[17/3233] Mass surface densitysolMass.pc**-2phys.densityfloatRad[0.1/7.2] Clump radiuspcphys.size.radiusfloatrcolEquivalent mass densitysolMass.pc**-3phys.densitydoublencol[4/1264] Estimated density at the emission peakm**-3phys.densityfloatMcol[7/58792] LTE masssolMassphys.massintPgas[0.3/925] Implied central gas pressurepPaphys.pressure;em.wl.centralfloatLCO[2/4807] Peak line luminosity, ^12^CO J=1->0K.km.s**-1.pc**-2phys.luminositydoublealpha[0.3/209] Virial {alpha} parameter ({alpha}=Mvir/Mcol)phys.mass;arith.ratiofloatRJe[0.1/1.3] Rayleigh-Jeans radiuspcphys.size.radiusfloatMBE[52/232539] Bonnor-Ebert masssolMassphys.massint