J/MNRAS/439/2584ivo://CDS.VizieR/J/MNRAS/439/2584doi:10.26093/cds/vizier.74392584CDSVoronkov M.A.Caswell J.L.Ellingsen S.P.Green J.A.Breen S.L.2024-08-08T20:12:45Z2014-03-27T08:47:36ZCDS support team

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

cds-question@unistra.frastrophysical-masersradio-astronomyastrometryThe Australia Telescope Compact Array (ATCA) has been used for high angular resolution imaging of 71 southern class I methanol maser sources quasi-simultaneously at 36 and 44GHz. The data reveal a high level of morphological and kinematical complexity, and allow us to demonstrate associations, at arcsecond precision, of the class I maser emission with outflows, expanding HII regions, dark clouds, shocks traced by the 4.5-micron emission and 8.0-micron filaments. More than 700 maser component features were found at each of the two methanol transitions, but with only 23 per cent recognisable at both transitions; the morphology of class I emission is much better revealed by our survey of both transitions, compared with either one alone. We found that the number of masers falls exponentially with the projected linear distance from the associated class II 6.7-GHz methanol maser. This distribution has a scale of 263+/-15-milliparsec, irrespective of the transition. The class I masers associated with OH masers were found to have a tendency to be more spread out, both spatially and in the velocity domain. This is consistent with the expectation that such sources are more evolved. Apart from a small number of high-velocity components (which are largely blue-shifted and predominantly seen at 36GHz), the velocity distribution was found to be Gaussian, peaking near the systemic velocity of the region, which had been estimated as the middle of the velocity interval of the associated class II methanol maser at 6.7GHz. The mean indicated a small, but significant blue shift asymmetry of -0.57km/s (uncertainties are 0.06 and 0.07km/s for the 36- and 44-GHz masers, respectively) with respect to the 6.7GHz masers. The standard deviation of the velocity distribution was found to be 3.65+/-0.05 and 3.32+/-0.07km/s for the 36- and 44GHz masers, respectively. We also suggest a refined rest frequency value of 36169.238+/-0.011MHz for the 4_-1_-3_0_E methanol transition.2014MNRAS.439.2584Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/439/2584CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/439/2584https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/439/2584http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/439/2584https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/439/2584https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/439/2584http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/439/2584GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/439/2584/table1 (Observation details for all targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/439/2584/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/439/2584/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/439/2584/table1?GETtext/xml+votable180.050000true135.8925-48.4677780.005555555555555556Cone search capability for table J/MNRAS/439/2584/table3 (Fit parameters for individual maser features at 36 and 44GHz in 71 southern sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/439/2584/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/439/2584/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/439/2584/table3?GETtext/xml+votable180.050000true135.88930417-48.467206390.0055555555555555566/37846 37850 37897 41655 41677 41772 41777-41778 41780 41804-41805 41812-41813 41815 41817 41820 41824 42159 42169-42172 42207 42210-42211 42214 42217 42224 42230 42379 42381 42387 42390-42391 42396 42417 42441 42444 42449 42451 42456 42496-42498 43013 430212.3853850453108836e-23 2.3853850453108836e-23https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/439/2584?format=asciiRadiodefaultJ/MNRAS/439/2584/table1Observation details for all targetsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name, GLLL.ll+B.bbmeta.idcharprimaryn_Name[*] Sources with better accuracy (1)meta.notecharNmNumber of detected peaksmeta.numberintnullableRAJ2000Pointing centre Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Pointing centre Declination (J2000)pos.eq.dec;meta.mainDate1Observation date (MMM DD, 2007)time.epoch;obsnullablenoise36[54/120] 36GHz 1{sigma} noisemJyphot.flux.density;em.mm.30-50GHzintVel36lLower value of velocity range for 36GHzkm/sinstr.bandwidthintVel36uUpper value of velocity range for 36GHzkm/sinstr.bandwidthintDate2Observation date (MMM DD, 2007)time.epoch;obsnullablenoise44[81/270] 44GHz 1{sigma} noisemJystat.snr;instr.det.noiseintVel44lLower value of velocity range for 44GHzkm/sinstr.bandwidthintVel44uUpper value of velocity range for 44GHzkm/sinstr.bandwidthintJ/MNRAS/439/2584/table3Fit parameters for individual maser features at 36 and 44GHz in 71 southern sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name, GLLL.ll+B.bbmeta.idcharm_NameLabel for the particular location in the given source, used only for cross-referencingmeta.code.multipcharNmNumber of observations for this locusmeta.numberintnullableFreq[36/44] Frequency of the molecular transition, either 36 or 44 (GHz)GHzem.freq;phys.atmol.transitionintVel[-107/20] Peak velocitykm/sspect.dopplerVelocdoublee_Vel[0/6.3] Peak velocity uncertaintykm/sstat.errorfloatRAJ2000Right Ascension J2000pos.eq.ra;meta.maine_RAJ2000Right Ascension uncertainty (seconds)sstat.error;pos.eq.rafloatDEJ2000Declination J2000pos.eq.dec;meta.maine_DEJ2000Declination uncertainty (arcseconds)arcsecstat.error;pos.eq.decfloatFWHMFull width at half maximumkm/sspect.line.widthfloate_FWHMUncertainty of the full width at half maximumkm/sstat.error;phys.angSizefloatFluxPeak flux densityJyphot.fluxfloate_FluxUncertainty of the flux densityJystat.error;phot.fluxfloat