J/A+A/570/A51ivo://CDS.VizieR/J/A+A/570/A51doi:10.26093/cds/vizier.35700051CDSShipman R.van der Tak F.F.SWyrowski F.Herpin F.Frieswijk W.2015-03-02T11:27:59Z2014-10-15T09:12:48ZCDS support team

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

cds-question@unistra.frmolecular-cloudsmillimeter-astronomysubmillimeter-astronomyspectroscopyThe earliest phases of high-mass star formation are poorly understood. Aims. Our goal is to determine the physical conditions and kinematic structure of massive starforming cloud clumps. We analyse H_2_O 557GHz line profiles observed with HIFI toward four positions in two infrared-dark cloud clumps. By comparison with ground-based C_17_O, N_2_H^+^, CH_3_OH, and NH_3_ line observations, we constrain the volume density and kinetic temperature of the gas and estimate the column density and abundance of H_2_O and N_2_H^+^. The observed water lines are complex with emission and absorption components. The absorption is redshifted and consistent with a cold envelope, while the emission is interpreted as resulting from proto-stellar outflows. The gas density in the clumps is ~10^7^cm^-3^. The o-H_2_O outflow column density is 0.3-3.0x10^14^cm^-2^. The o-H_2_O absorption column density is between 1.5x10^14^ and 2.6x10^15^cm^-2^ with cold o-H_2_O abundances between 1.5x10^-9^ and 3.1x10^-8^. All clumps have high gas densities (~10^7^cm^-3^) and display infalling gas. Three of the four clumps have outflows. The clumps form an evolutionary sequence as probed by H_2_O N_2_H+, NH_3_, and CH_3_OH. We find that G28-MM is the most evolved, followed by G11-MM and then G28-NH3. The least evolved clump is G11-NH3 which shows no signposts of starformation; G11-NH3 is a high-mass pre-stellar core.2014A&A...570A..51Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/570/A51CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/570/A51https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/570/A51http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/570/A51https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/570/A51https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/570/A51http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/570/A51GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/570/A51/list (List of FITS spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/570/A51/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/570/A51/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/570/A51/list?GETtext/xml+votable180.050000true272.6409-19.36420.0055555555555555566/29097 30256 30258https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/570/A51?format=asciiRadiodefaultJ/A+A/570/A51/listList of FITS spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name as in Pillai et al. 2006 (2006A&A...450..569P)meta.id;meta.maincharRAJ2000Right ascension of the image center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of the image center (J2000)degpos.eq.dec;meta.mainNpNumber of velocity pointsmeta.numberintbVel[-33/49] Lower value of velocity intervalkm/sphys.velocfloatBVel[17/224] Upper value of velocity intervalkm/sphys.velocfloatdVel[65/868] Velocity resolutionm/sspect.resolutionintsize[17/124] Size of FITS fileKibytephys.size;meta.fitsintspShow the spectrummeta.ref.urlcharfitsDownload the FITS filemeta.ref.urlcharFileNameName of FITS file in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the filemeta.title;meta.file