J/A+AS/124/205ivo://CDS.VizieR/J/A+AS/124/205CDSHelmich F.P.van Dishoeck E.F.1997-12-09T18:36:26Z1997-12-09T19:36:17ZCDS support team

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

cds-question@unistra.frinterstellar-mediuminfrared-sourcesradio-astronomyResults are presented of the 345 GHz spectral survey toward three sources in the W 3 Giant Molecular Cloud: W 3 IRS4, W 3 IRS5 and W 3(H_2_O). Nearly 90% of the atmospheric window between 334 and 365GHz has been scanned using the James Clerk Maxwell Telescope (JCMT) down to a noise level of ~80mK per resolution element. These observations are complemented by a large amount of data in the 230GHz atmospheric window. From this data set physical conditions and beam-averaged column densities are derived for more than 14 chemically different species (over 24 different isotopes). The physical parameters derived in Paper I (Helmich et al., 1994A&A...283..626H) are confirmed by the analysis of the excitation of other species, although there is evidence that the silicon- and sulfur-bearing molecules exist in a somewhat denser and warmer environment. The densities are high, >=10^6^cm^-3^, in the three sources and the kinetic temperatures for the bulk of the gas range from 55K for IRS4 to 220K for W 3(H_2_O). The chemical differences between the three sources are very striking: silicon- and sulfur-bearing molecules such as SiO and SO_2_ are prominent toward IRS5, whereas organic molecules like CH_3_OH, CH_3_OCH_3_ and CH_3_OCHO are at least an order of magnitude more abundant toward W 3(H_2_O). Vibrationally excited molecules are also detected toward this source. Only simple molecules are found toward IRS4. The data provide constraints on the amount of deuterium fractionation and the ionization fraction in the observed regions as well. These chemical characteristics are discussed in the context of an evolutionary sequence, in which IRS5 is the youngest, W 3(H_2_O) somewhat older and IRS4, although still enigmatic, the oldest.1997A&AS..124..205Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/124/205CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/124/205https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/124/205http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/124/205https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/124/205https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/124/205http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/124/205GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfraredRadiodefaultJ/A+AS/124/205/table7*Gaussian fit parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSpeciesSpeciesphys.atmol.elementcharn_SpeciesNote on species (2)meta.notecharnuFrequencyMHzem.freqdoubleJTransition designationmeta.id;phys.atmol.transitioncharl_TMBaLimit flag on TMBa (1)meta.code.errorcharTMBa? W3 IRS4 temperatureKphys.temperaturefloatn_TMBaNote on TMBa (2)meta.notecharDVa? W3 IRS4 {DELTA}Vkm/sphys.veloc;arith.difffloatWa? W3 IRS4 integrated intensityK.km/sspect.line.intensityfloatl_TMBbLimit flag on TMBb (1)meta.code.errorcharTMBb? W3 IRS5 temperatureKphys.temperaturefloatn_TMBbNote on TMBb (2)meta.notecharDVb? W3 IRS5 {DELTA}Vkm/sphys.veloc;arith.difffloatWb? W3 IRS5 integrated intensityK.km/sspect.line.intensityfloatl_TMBcLimit flag on TMBc (1)meta.code.errorcharTMBc? W3 (H2O) temperatureKphys.temperaturefloatn_TMBcNote on TMBa (2)meta.notecharDVc? W3 (H2O) {DELTA}Vkm/sphys.veloc;arith.difffloatn_DVcNote on DVc (2)meta.notecharWc? W3 (H2O) integrated intensityK.km/sspect.line.intensityfloatJ/A+AS/124/205/table8CH_3_OH Gaussian fit parameters W 3 IRS4recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnuFrequencyMHzem.freqdoubleNJTransition designationmeta.id;phys.atmol.transitioncharTMBTemperatureKphys.temperaturefloatn_TMBNote (1)meta.notecharDV{DELTA}Vkm/sphys.veloc;arith.difffloatWIntegrated intensityK.km/sspect.line.intensityfloatJ/A+AS/124/205/table9CH_3_OH Gaussian fit parameters W 3 IRS5recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnuFrequencyMHzem.freqdoubleNJTransition designationmeta.id;phys.atmol.transitioncharTMBTemperatureKphys.temperaturefloatn_TMBNote (1)meta.notecharDV{DELTA}Vkm/sphys.veloc;arith.difffloatWIntegrated intensityK.km/sspect.line.intensityfloatJ/A+AS/124/205/table10CH_3_OH Gaussian fit parameters W 3(H_2_O)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnut[0/2] Quantum number of the torsional modephys.atmol.qnintnuFrequencyMHzem.freqdoubleNJTransition designationmeta.id;phys.atmol.transitioncharl_TMBLimit flag on TMB (1)meta.code.errorcharTMB? TemperatureKphys.temperaturefloatn_TMBNote (2)meta.notecharDV? {DELTA}Vkm/sphys.veloc;arith.difffloatW? Integrated intensityK.km/sspect.line.intensityfloatJ/A+AS/124/205/table11CH_3_OCH_3_ Gaussian fit parameters W 3(H_2_O)W? Integrated intensityK.km/sspect.line.intensityfloatDV? {DELTA}Vkm/sphys.veloc;arith.difffloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnuFrequencyMHzem.freqcharJkJ_k_0_,k_p__ transition designationmeta.id;phys.atmol.transitioncharl_TMBLimit flag on TMBmeta.code.errorcharTMB? TemperatureKphys.temperaturefloatn_TMBNote (1)meta.notecharJ/A+AS/124/205/table12CH_3_OCHO Gaussian fit parameters W 3(H_2_O)n_WNote (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnuFrequencyMHzem.freqcharJTransition designationmeta.id;phys.atmol.transitioncharl_TMBLimit flag on TMBmeta.code.errorcharTMB? TemperatureKphys.temperaturefloatn_TMBNote (1)meta.notecharDV? {DELTA}Vkm/sphys.veloc;arith.difffloatW? Integrated intensityK.km/sspect.line.intensityfloat