J/ApJ/820/37ivo://CDS.VizieR/J/ApJ/820/37doi:10.26093/cds/vizier.18200037CDSYuan J.Wu Y.Liu T.Zhang T.Li J.Z.Liu H.-L.Meng F.Chen P.,Hu R.Wang K.2017-06-28T06:57:52Z2016-06-24T14:05:32ZCDS support team

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

cds-question@unistra.frradio-astronomyinterstellar-mediumWe present the first survey of dense gas toward Planck Galactic Cold Clumps (PGCCs). Observations in the J=1-0 transitions of HCO^+^ and HCN toward 621 molecular cores associated with PGCCs were performed using the Purple Mountain Observatory's 13.7m telescope. Among them, 250 sources were detected, including 230 cores detected in HCO^+^ and 158 in HCN. Spectra of the J=1-0 transitions from ^12^CO, ^13^CO, and C^18^O at the centers of the 250 cores were extracted from previous mapping observations to construct a multi-line data set. The significantly low detection rate of asymmetric double-peaked profiles, together with the good consistency among central velocities of CO, HCO^+^, and HCN spectra, suggests that the CO-selected Planck cores are more quiescent than classical star-forming regions. The small difference between line widths of C^18^O and HCN indicates that the inner regions of CO-selected Planck cores are no more turbulent than the exterior. The velocity-integrated intensities and abundances of HCO^+^ are positively correlated with those of HCN, suggesting that these two species are well coupled and chemically connected. The detected abundances of both HCO^+^ and HCN are significantly lower than values in other low- to high-mass star-forming regions. The low abundances may be due to beam dilution. On the basis of an inspection of the parameters given in the PGCC catalog, we suggest that there may be about 1000 PGCC objects that have a sufficient reservoir of dense gas to form stars.2016ApJ...820...37Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/820/37CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/88 : Planck Early Release Compact Source Catalogue (Planck, 2011)J/A+A/584/A93 : Galactic cold cores. V. Dust opacity (Juvela+, 2015)J/A+A/569/A125 : Spiral structure of the Milky Way (Hou+, 2014)J/A+A/563/A97 : IRAM 30m reduced spectra of 59 sources (Gerner+, 2014)J/ApJS/209/37 : Planck cold clumps in ^12^CO, ^13^CO and C^18^O (Meng+, 2013)J/ApJS/202/4 : Planck cold clumps survey in the Orion complex (Liu+, 2012)J/ApJ/756/76 : Planck cold dust clumps CO survey (Wu+, 2012)J/ApJ/756/60 : A 3mm line survey in 37 IR dark clouds (Sanhueza+, 2012)J/A+A/527/A88 : Chemistry in infrared dark clouds (Vasyunina+, 2011)J/A+AS/133/29 : Molecular line survey towards UC HII (Hatchell+ 1998)http://www.ism-spp.de/ : ISM program home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/820/37https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/820/37http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/820/37https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/820/37https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/820/37http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/820/37GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/820/37/cores (Observational parameters of HCO+ and HCN and derived parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/820/37/cores?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/820/37/cores?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/820/37/cores?GETtext/xml+votable180.050000true272.8371667-2.00630560.0055555555555555566/341 343 597 599 844 858 859 860 861 862 1031 1037 1038 1048 1050 1054 1059 1061 1067 1073 1074 1075 1077 1080 1082 1117 1159 1168 1176 1205 1247 1261 1290 1344 1346 1350 1542 1588 1591 1604 1605 1606 1731 1788 1812 1846 1847 1851 1852 1937 1940 1959 1964 1968 2962 2973 3157 3188 3255 3330 3331 3349 3353 3355 3356 3371 3375 3379 3458 3459 3627 3630 3634 3635 3716 3745 3747 3748 3777 3849 3873 3884 12985 13584 13726 13927 14014 14052 14053 14069 14199 14306 14347 14595 14601 14618 15362 15380 15541 15578 15588 15590 15781 15782 15812 15816 15825 15857 15941 15964 15965 16129 16133 16191 16197 16198 16203 21308 21347 21350 21396 21397 21440 21637 21645 22205 22807 22876 23005 23029 23030 23031 23561 23563 23576 23597 23600 23644 23646 23669 23697 23738 23739 23770 23970 24066 24076 24077 24163 24169 24353 24378 24424 24427 24450 24474 24487 24526 24569 30272 30368 30421 32011https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/820/37?format=asciiRadiodefaultJ/ApJ/820/37/coresObservational parameters of HCO+ and HCN and derived parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPLCKECCPlanck Early Cold Core identifier (GLLL.ll+BB.bb)meta.id.parentcharIDSource identifier (aN)meta.id.part;meta.maincharRAJ2000? Hour of Right Ascension (J2000)pos.eq.ra;meta.mainnullableDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainHCO+rms? HCO+ spectrum root-mean-squareKinstr.det.noisefloatnullableHCO+Tp? HCO+ spectrum peak intensityKphot.fluxfloatnullablee_HCO+Tp? Error in HCO+TpKstat.errorfloatnullableHCO+W? HCO+ spectrum areaK.km/sphot.fluxfloatnullablee_HCO+W? Error in HCO+WK.km/sphot.fluxfloatnullableHCO+V[-53/25]? HCO+ local standard of rest velocitykm/sphys.veloc;pos.lsrfloatnullablee_HCO+V[0.01/0.6]? Error in HCO+Vkm/sstat.errorfloatnullableHCO+FWHM[0.4/4.7]? HCO+ line widthkm/sspect.line.widthfloatnullablee_HCO+FWHM[0.03/25.5]? Error in HCO+FWHMkm/sspect.line.widthfloatnullableHCNrms? HCN spectrum root-mean-squareKinstr.det.noisefloatnullableHCNTp? HCN spectrum peak intensityKphot.fluxfloatnullablee_HCNTp? Error in HCNTpKstat.errorfloatnullableHCNW? HCO+ spectrum areaK.km/sphot.fluxfloatnullablee_HCNW? Error in HCNWK.km/sphot.fluxfloatnullableHCNV[-51/15]? HCN local standard of rest velocitykm/sphys.veloc;pos.lsrfloatnullablee_HCNV[0.02/0.4]? Error in HCNVkm/sstat.errorfloatnullableHCNFWHM[0.6/2.7]? HCO+ line widthkm/sspect.line.widthfloatnullablee_HCNFWHM[0.01/1.6]? Error in HCNFWHMkm/sspect.line.widthfloatnullabletau[0.1/3.2]? HCN spectrum main component optical depthphys.absorption.opticalDepth;meta.mainfloatnullablee_tau[0/1.9]? Error in taustat.errorfloatnullableRGal[7.6/18.7]? Galactocentric distancekpcpos.distance;pos.galactocentricfloatnullableDist[0.1/14.7]? Distance from the Sunkpcpos.distance;pos.heliocentricfloatnullabletau13CO[0.1/2.4] Optical depth of ^13^COphys.absorption.opticalDepthfloattau18CO[0.04/0.7]? Optical depth of ^18^COphys.absorption.opticalDepthfloatnullabletauHCO+[0.05/4.1]? HCO+ optical depth of HCO+phys.absorption.opticalDepthfloatnullableTexCO[7/35]? Excitation temperature of COKspect.line.intensity;em.line.CO;spect.linefloatnullablee_TexCO[0.1/2]? Error in TexCOKstat.errorfloatnullableN13CO[3.7/56.7]? Column density of ^13^CO1e+15cm**-2phys.columnDensityfloatnullablee_N13CO[0.2/5]? Error in N13CO1e+15cm**-2stat.errorfloatnullableN18CO[0.2/8.7]? Column density of ^18^CO1e+15cm**-2phys.columnDensityfloatnullablee_N18CO[0.07/2]? Error in N18CO1e+15cm**-2stat.errorfloatnullableNHCO+[0.07/24.2]? Column density of HCO+1e+12cm**-2phys.columnDensityfloatnullablee_NHCO+[0.03/5]? Error in NHCO+1e+12cm**-2stat.errorfloatnullableNHCN[0.2/16.2]? Column density of HCN1e+12cm**-2phys.columnDensityfloatnullablee_NHCN[0.1/15]? Error in NHCN1e+12cm**-2stat.errorfloatnullableNH2[1.4/71]? Column density of H_2_1e+12cm**-2phys.columnDensityfloatnullablee_NH2[0.2/16]? Error in NH21e+12cm**-2stat.error;phys.columnDensityfloatnullableXHCO+[0.3/152.2]? Fractional abundance of HCO+phys.abundfloatnullablee_XHCO+[0.1/49]? Error in XHCO+stat.errorfloatnullableXHCN[1.2/56]? Fractional abundance of HCNphys.abundfloatnullablee_XHCN[0.4/194]? Error in XHCNstat.errorfloatnullableL12Display cores data from Liu+, 2012, J/ApJS/202/4meta.ref.urlintnullableM13Display data from Meng+, 2013, J/ApJS/209/37meta.ref.urlintnullableSimbadDisplay the Planck Early Cold Core source in Simbadmeta.ref.urlchar