J/A+A/632/A58ivo://CDS.VizieR/J/A+A/632/A58doi:10.26093/cds/vizier.36320058CDSRigby A.J.Moore T.J.T.Eden D.J.Urquhart J.S.Ragan S.E.Peretto N.,Plume R.Thompson M.A.Currie M.J.Park G.2021-09-15T12:49:25Z2021-03-09T10:07:03ZCDS support team

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

cds-question@unistra.frsurveysgalaxy-planesmilky-way-galaxymolecular-cloudsco-line-emissionThe latest generation of high-angular-resolution unbiased Galactic plane surveys in molecular-gas tracers are enabling the interiors of molecular clouds to be studied across a range of environments. The CO Heterodyne Inner Milky Way Plane Survey (CHIMPS) simultaneously mapped a sector of the inner Galactic plane, within 27.8<l<46.2{deg} and |b|<0.5{deg}, in ^13^CO (3-2) and C^18^O (3-2) at an angular resolution of 15 arcsec. The combination of the CHIMPS data with ^12^CO (3-2) data from the CO High Resolution Survey (COHRS) has enabled us to perform a voxel-by-voxel local-thermodynamic-equilibrium (LTE) analysis, determining the excitation temperature, optical depth, and column density of ^13^CO at each l,b,v position. Distances to discrete sources identified by FellWalker in the ^13^CO (3-2) emission maps were determined, allowing the calculation of numerous physical properties of the sources, and we present the first source catalogues in this paper. We find that, in terms of size and density, the CHIMPS sources represent an intermediate population between large-scale molecular clouds identified by CO and dense clumps seen in thermal dust continuum emission, and therefore represent the bulk transition from the diffuse to the dense phase of molecular gas. We do not find any significant systematic variations in the masses, column densities, virial parameters, mean excitation temperature, or the turbulent pressure over the range of Galactocentric distance probed, but we do find a shallow increase in the mean volume density with increasing Galactocentric distance. We find that inter-arm clumps have significantly narrower linewidths, and lower virial parameters and excitation temperatures than clumps located in spiral arms. When considering the most reliable distance-limited subsamples, the largest variations occur on the clump-to-clump scale, echoing similar recent studies that suggest that the star-forming process is largely insensitive to the Galactic-scale environment, at least within the inner disc.2019A&A...632A..58Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/632/A58CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/632/A58https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/632/A58http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/632/A58https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/632/A58https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/632/A58http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/632/A58GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/632/A58/table1 (Details of the sources extracted from the ^13^CO (3-2) data cubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/632/A58/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/632/A58/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/632/A58/table1?GETtext/xml+votable180.050000true280.1599807-4.67303720.0055555555555555565/7564 7578 7605 7651 6/30245 30247 30262-30263 30265 30268-30269 30306 30316 30318-30319 30330 30405 30416-30417 30419 30594-30595 30598 30600-30601 30616 30618-30619 30622-30623 30641 30644-30645https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/632/A58?format=asciiRadiodefaultJ/A+A/632/A58/table1Details of the sources extracted from the ^13^CO (3-2) data cubesSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCHIMPSSource identifier, CHIMPSNNNN (CHIMPS_ID)meta.id;meta.maincharGALGalactic designation, GLLL.lll+BB.bbb (GAL_ID)meta.idcharRegionRegion number (REGION)meta.id;obs.fieldintPIdentClump pixel ID (PIDENT)meta.idintGLONPosition of the ^13^CO centroid along l axis (l_cen)degpos.galactic.lonGLATPosition of the ^13^CO centroid along b axis (b_cen)degpos.galactic.latdoubleVPosition of the ^13^CO centroid along v axis (v_cen)km/sposdoubleGLONpPosition of the ^13^CO peak along l axis (l_peak)degpos.galactic.lonGLATpPosition of the ^13^CO peak along b axis (b_peak)degpos.galactic.latdoubleVpPosition of the ^13^CO peak along v axis (v_peak)km/spos;stat.maxdoublesigGLONThe rms size of the clump along l axis (sigma_l)arcsecstat.errordoublesigGLATThe rms size of the clump along b axis (sigma_b)arcsecstat.errordoublesigVThe rms size of the clump along v axis (sigma_v)km/sstat.errorfloatPeak13COThe peak ^13^CO intensity in the clump (Peak_13CO)Kspect.line.intensity;stat.maxdoubleSum13COThe sum of the ^13^CO intensity in the clump (Sum_13CO) (1)Kspect.line.intensitydoublePeakC18OThe peak C^18^O intensity in the clump (Peak_C18O)Kspect.line.intensity;stat.maxdoubleSumC18OThe sum of the C^18^O intensity in the clump (Sum_C18O) (2)Kspect.line.intensitydoublePeakSNThe peak S/N in the clump (at 27.4 arcsec) (Peak_SN)stat.snrdoubleMeanSNThe mean S/N in the clump (at 27.4 arcsec) (Mean_SN)stat.snrdoubleNpixTotal number of pixels in the clump area (n_pixels)meta.numberintNvoxTotal number of voxels in the clump volume (n_voxels)meta.numberintFlagR[1/3] Reliability flag (Flag_R) (G1)meta.code.errorint_GlonRight Ascension (J2000) from SIMBAD (not part of the original data)degpos.galactic.lon_GlatDeclination (J2000) from SIMBAD (not part of the original data)degpos.galactic.lat_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/A+A/632/A58/table4Derived physical properties of the clumpsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCHIMPSSource identifier, CHIMPSNNNN (CHIMPS_ID)meta.id;meta.maincharGALGalactic designation, GLLL.lll+BB.bbb (GAL_ID)meta.idcharRegionRegion number (REGION)meta.id;obs.fieldintPIdentClump pixel ID (PIDENT)meta.idintGLONPosition of the ^13^CO centroid along l axis (l_cen)degpos.galactic.lonGLATPosition of the ^13^CO centroid along b axis (b_cen)degpos.galactic.latdoubleVPosition of the ^13^CO centroid along v axis (v_cen)km/sposdoublesigGLONThe rms size of the clump along l axis (sigma_l)arcsecstat.errordoublesigGLATThe rms size of the clump along b axis (sigma_b)arcsecstat.errordoublesigVThe rms size of the clump along v axis (sigma_v)km/sstat.errorfloate_sigVUncertainty on the rms velocity size (sigma_v_Err)km/sstat.errorfloatKDAKinematic distance solution (KDA)meta.codecharKDAmethMethod used to determine kinematic distance (KDA_method)meta.notecharDist? Heliocentric distance (Dist)kpcpos.distancefloatnullablee_Dist? Uncertainty on the heliocentric distance (Dist_Err)kpcstat.errorfloatnullableRGC? Galactocentric distance (R_GC)kpcpos.distance;pos.galactocentricfloatnullablee_RGC? Uncertainty on the Galactocentric distance (R_GC_Err)kpcstat.errorfloatnullableArmSpiral arm assignment (Arm)src.morph.paramcharMass? Clump mass (Mass)solMassphys.massdoublenullablee_Mass? Uncertainty on the clump mass (Mass_Err)solMassstat.error;phys.massdoublenullableRsig? Intensity-weighted rms radius (R_sig)pcstat.stdev;phys.size.radiusfloatnullableReq? Equivalent radius (R_eq)pcphys.size.radiusfloatnullablenH2? Mean volume density (nH2)cm**-3phys.densitydoublenullablealpha? Virial parameter (alpha)phys.mass;arith.ratiodoublenullableSurfDens? Mean surface density (SurfDens) (1)solMass.pc**-2phot.flux.density.sb;stat.meandoublenullablePturb? Mean turbulent (non-thermal) pressure (P_turb)K.cm**-3phys.pressuredoublenullablePtherm? Mean thermal pressure (P_therm)K.cm**-3phys.pressuredoublenullableN13CO? Mean ^13^CO column density (N13CO) (2)cm**-2phys.columnDensity;stat.meandoublenullableTex? Mean excitation temperature (T_ex)Kphys.atmol.excitation;stat.meandoublenullableTau? Mean ^13^CO (3-2) optical depth (Tau)phys.absorption.opticalDepth;stat.meanfloatnullableFlagR[1/3] Reliability flag (Flag_R) (G1)meta.code.errorint