J/A+A/620/A158ivo://CDS.VizieR/J/A+A/620/A158doi:10.26093/cds/vizier.36200158CDSSaral G.Audard M.Wang Y.2018-12-18T06:46:59Z2018-12-12T07:56:47ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinterstellar-mediumHigh mass stars form in groups or clusters in dense molecular clumps with sizes of 1pc and masses of 200M_{sun}_. Infrared-dark clumps and the individual cores within them with sizes <0.1pc and masses <100M_{sun}_ are important laboratories for high-mass star formation in order to study the initial conditions. We investigate the physical and chemical properties of high-mass clumps in order to better understand the early evolutionary stages and find targets which show star formation signs such as infall motions or outflows. We selected the high-mass clumps from ATLASGAL survey that were identified as dark at 8/24um wavelengths. We use MALT90 Survey data which provides a molecular line set (HCO^+^, HNC, HCN, N^13^CH^+^, H^13^CO^+^, HN^13^C (1-0), SiO) to investigate the physical and chemical conditions in early stages of star formation. Results. (1) Eleven sources have significant SiO detection (over 3{sigma}) which usually indicates outflow activity. (2) Thirteen sources are found with blue profiles in both/either HCO+ and/or HNC lines and clump mass infall rates are estimated to be in the range of 0.2x10^-3^M_{sun}_/yr-1.8x10^-2^M_{sun}_/yr. (3) The excitation temperature is obtained as <24K for all sources. (4) The column densities for optically thin lines of H^13^CO^+^ and HN^13^C (1-0) are in the range of 0.4-8.8(x10^12^)cm^-2^, and 0.9-11.9(x10^12^)cm^-2^, respectively, while it is in the range of 0.1-7.5(x10^14^)cm^-2^ for HCO^+^ and HNC lines. The column densities for N^13^CH^+^ were ranging between 4.4-275.7(x10^12^)cm^-2^ as expected from cold dense regions. (5) Large line widths of N^13^CH^+^ might indicate turbulence and large line widths of HCO^+^, HNC, and SiO indicate outflow activities. (6) Mean optical depths are 20.32, and 23.19 for optically thick HCO^+^ and HCN lines, and 0.39 and 0.45 for their optically thin isotopologues H^13^CO^+^ and HN^13^C (1-0), respectively. This study reveals the physical and chemical properties of 30 high-mass IR-dark clumps and the interesting targets among them based on their emission line morphology and kinematics.2018A&A...620A.158Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/620/A158CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/549/A45 : ATLASGAL Compact Source Catalog: 330<l<21 (Contreras+, 2013)J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/620/A158https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/620/A158http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/620/A158https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/620/A158https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/620/A158http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/620/A158GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/620/A158/list (List of fits datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/620/A158/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/620/A158/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/620/A158/list?GETtext/xml+votable180.050000true272.186391-19.90833240.0055555555555555566/28803 28919 29097 29113-29115 29508 41677 41759 41767 41776 41814 42173 42211 42215 42227 42378 42383 42392 42457 42459-42461 42497 42512https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/620/A158?format=asciidefaultJ/A+A/620/A158/clumpsList of studied clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification number of the clumpmeta.idintNameName of the clump (GLLL.lll+BB.bbb)meta.id;meta.maincharSNameSimbad name (AGAL GLLL.lll+BB.bbb)meta.idcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/620/A158/listList of fits datacubesNzNumber of slicesmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGLONGalactic longitude of center (J2000)degpos.galactic.lonGLATGalactic latitude of center (J2000)degpos.galactic.latNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintbVlsrLower value of LSR velocity intervalm/sphys.veloc;pos.lsrdoubleBVlsrUpper value of LSR velocity intervalm/sphys.veloc;pos.lsrintdVlsrLSR velocity resolutionm/sspect.resolutionfloatsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fits_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.decnullableindexed