J/ApJ/764/L19ivo://CDS.VizieR/J/ApJ/764/L19doi:10.26093/cds/vizier.17649019CDSYusef-Zadeh F.Cotton W.Viti S.Wardle M.Royster M.2025-10-16T20:14:50Z2014-11-20T15:01:34ZCDS support team

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

cds-question@unistra.frradio-continuum-emissionastrophysical-masersradio-astronomymilky-way-galaxyWe report the discovery of a widespread population of collisionally excited methanol J=4_-1_ to 3_0_E sources at 36.2GHz from the inner 66'x18' (160x43pc) of the Galactic center. This spectral feature was imaged with a spectral resolution of 16.6km/s taken from 41 channels of a Very Large Array continuum survey of the Galactic center region. The revelation of 356 methanol sources, most of which are maser candidates, suggests a large abundance of methanol in the gas phase in the Galactic center region. There is also spatial and kinematic correlation between SiO (2-1) and CH_3_OH emission from four Galactic center clouds: the +50 and +20km/s clouds and G0.13-0.13 and G0.25+0.01. The enhanced abundance of methanol is accounted for in terms of induced photodesorption by cosmic rays as they travel through a molecular core, collide, dissociate, ionize, and excite Lyman Werner transitions of H_2_. A time-dependent chemical model in which cosmic rays drive the chemistry of the gas predicts CH_3_OH abundance of 10^-8^ to 10^-7^ on a chemical timescale of 5x10^4^ to 5x10^5^ years. The average methanol abundance produced by the release of methanol from grain surfaces is consistent with the available data.2013ApJ...764L..19Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/764/L19CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/563/A68 : CH_3_OH and H_2_O Galactic center masers (Chambers+, 2014)J/ApJ/702/178 : YSOs in the central 400pc of the Galaxy (Yusef-Zadeh+, 2009)J/ApJ/699/186 : VLA observations of the Galactic center (Zhao+, 2009)J/ApJS/155/421 : Survey of Galactic Center region at 20cm (Yusef-Zadeh+, 2004)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/764/L19https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/764/L19http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/764/L19https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/764/L19https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/764/L19http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/764/L19GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/764/L19/table1 (Detected CH_3_OH sources in the survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/764/L19/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/764/L19/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/764/L19/table1?GETtext/xml+votable180.050000true266.6967192-28.42106970.0055555555555555566/28827 28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/764/L19?format=asciiRadiodefaultJ/ApJ/764/L19/table1Detected CH_3_OH sources in the surveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/355] Running sequence number of the sourcemeta.numberintprimaryGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latFlux[0.1/469] Observed line flux (at 36.2GHz)Jy.km/sphot.flux.density;em.mm.30-50GHzfloatVel[-183/266] Velocitykm/sspect.dopplerVelocfloatTb[7.4/7261] Brightness temperature ({deg}Kx100)cKphys.temperaturefloate_TbUncertainty in Tb ({deg}Kx100)cKstat.errorfloatamaj[0.7/6] Major size fitarcsecphys.angSizefloatamin[0.07/6] Minor size fitarcsecphys.angSize;srcfloatPA[-309/354] Position angle of fitted ellipsedegpos.posAng;meta.modelledfloatRef"SPF 2010": Sjouwerman+, 2010ApJ...710L.111Smeta.ref;pos.framechar_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.raindexed_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.decindexed