J/A+A/527/A88ivo://CDS.VizieR/J/A+A/527/A88doi:10.26093/cds/vizier.35270088CDSVasyunina T.Linz H.Henning T.ZinchenkoI.BeutherH.Voronkov M.2018-01-08T09:35:08Z2011-03-08T12:56:58ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinfrared-sourcesspectroscopyinterstellar-mediumMassive stars play an important role in shaping the structure of galaxies. Infrared dark clouds (IRDCs), with their low temperatures and high densities, have been identified as the potential birthplaces of massive stars. In order to understand the formation processes of massive stars, the physical and chemical conditions in infrared dark clouds have to be characterized. The goal of this paper is to investigate the chemical composition of a sample of southern infrared dark clouds. One important aspect of the observations is to check, whether the molecular abundances in IRDCs are similar to the low-mass pre-stellar cores, or if they show signatures of more evolved evolutionary stages. We performed observations toward 15 IRDCs in the frequency range between 86 and 93GHz using the 22-m Mopra radio telescope. In total, 13 molecular species comprising N_2_H^+^, ^13^CS, CH_3_CN, HC_3_N, HNC, HCO^+^, HCN, HNCO, C_2_H, SiO, H^13^CO^+^, H^13^CN, and CH_3_C_2_H were observed for all targets. Hence, we included in general species appropriate for elevated densities, where some of them trace the more quiescent gas, while others are sensitive to more dynamical processes.2011A&A...527A..88Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/527/A88CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/499/149 : Southern Infrared Dark Clouds physical prop. (Vasyunina+, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/527/A88https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/527/A88http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/527/A88https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/527/A88https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/527/A88http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/527/A88GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/527/A88/sources (List of observed sources, in 13CS, C2H, CH3CCH, CH3CN, H13CN, H13CO+, HCCCN, HCN, HCO+, HNC, HNCO, N2H+, SiO)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/527/A88/sources?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/527/A88/sources?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/527/A88/sources?GETtext/xml+votable180.050000true204.25659167-62.742780560.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/527/A886/29112 41599 41671 41673 41676-41677 41682 41684 41766-41767 41772 41778 41780 41802https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/527/A88?format=asciiInfraredOpticaldefaultJ/A+A/527/A88/sourcesList of observed sources, in 13CS, C2H, CH3CCH, CH3CN, H13CN, H13CO+, HCCCN, HCN, HCO+, HNC, HNCO, N2H+, SiOrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential numbermeta.recordintNameTarget name (IRDCLLL.ll-N)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.main[VLH2009]Associated Vasyunina et al., J/A+A/499/149, dark cloud name (added by CDS)meta.id.assoccharDistDistance (from table 1 of the paper) (1)kpcpos.distance;pos.heliocentricfloatn_Dist[b] b: from Saito et al. (2001PASJ...53.1037S)meta.notecharTTemperature (from table 1 of the paper) (2)Kphys.temperaturefloatN(H2)H_2_ column density (from table 1 of the paper) (3)1e+22cm**-2phys.columnDensityfloatCat[MAQ] Category (from table 1 of the paper) (4)meta.codecharspSpectrummeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar