J/A+A/644/A123ivo://CDS.VizieR/J/A+A/644/A123doi:10.26093/cds/vizier.36440123CDSChitarra O.Martin-Drumel M-A.Gans B.Loison J-C.Spezzano S.,Lattanzi V.Mueller H.S.P.Pirali O.2021-02-19T06:47:34Z2020-12-10T07:28:29ZCDS support team

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

cds-question@unistra.frinterstellar-mediummolecular-cloudsradio-astronomyspectroscopyThe hydroxymethyl radical (CH_2_OH) is one of the two structural isomers, together with the methoxy radical (CH_3_O), that can be produced by abstraction of a hydrogen atom from methanol (CH_3_OH). In the interstellar medium (ISM), both CH_2_OH and CH_3_O are suspected to be intermediate species in many chemical reactions, including those of formation and destruction of methanol. The determination of the CH_3_O/CH_2_OH ratio in the ISM would bring important information concerning the formation processes of these species in the gas and solid phases. Interestingly, only CH_3_O has been detected in the ISM so far, despite the recent first laboratory measurement of the CH_2_OH rotation-tunneling spectrum. This lack of detection is possibly due to the non-observation in the laboratory of the most intense rotational-tunneling transitions at low temperature. To support further searches for the hydroxymethyl radical in space, we have performed a thorough spectroscopic study of its rotation-tunneling spectrum, with particular focus on transitions involving the lowest quantum numbers of the species. We have recorded the rotation-tunneling spectrum of CH_2_OH at room temperature in the millimeter-wave domain using a frequency multiplication chain spectrometer associated to a fluorine-induced H-abstraction method. The radical was produced from methanol precursor. About 180 transitions were observed including those involving the lowest N and Ka quantum numbers, predicted intense under cold astrophysical conditions. These transitions were fitted together with available millimeter-wave lines from the literature. The systematic observation of all components of the rotational transitions yields a large improvement of the spectroscopic parameters which now allow confident searches of the hydroxymethyl radical in cold to warm environments of the ISM.2020A&A...644A.123Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/644/A123CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/644/A123https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/644/A123http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/644/A123https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/644/A123https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/644/A123http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/644/A123GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapRadiodefaultJ/A+A/644/A123/ch2ohiniInitial prediction up to 1000GHzv'Lower v quantum numberphys.mol.qn;stat.minintJ'Lower J quantum numberinstr.det.qe;stat.minintF1'Lower F1 quantum numberphys.mol.qnintIH'Lower IH quantum numberphys.mol.qnintF'Lower F quantum numberphys.mol.qnintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFreqFrequency of the lineMHzem.freqdoublee_FreqEstimated or experimental errorMHzstat.errordoublelogIntBase 10 logarithm of the integrated intensity in units of nm2.MHzlog(nm**2.MHz)meta.code;spect.line.intensityfloatDOFDegrees of freedom in the rotational partition functionstat.fit.dofintELowLower state energy in wavenumbersphys.energy;phys.atmol.leveldoublegupUpper state degeneracyphys.electron.degenintTagSpecies tag or molecular identifiermeta.codelongN"Upper N quantum numberphys.mol.qnintKa"Upper Ka quantum numberphys.mol.qn;stat.maxintKc"Upper Kc quantum numberphys.mol.qn;stat.maxintv"Upper v quantum numberphys.mol.qn;stat.maxintJ"Upper J quantum numberinstr.det.qe;stat.maxintF1"Upper F1 quantum numberphys.mol.qnintIH"Upper IH quantum numberphys.mol.qnintF"Upper F quantum numberphys.mol.qnintN'Lower N quantum numberphys.mol.qnintKa'Lower Ka quantum numberphys.mol.qn;stat.minintKc'Lower Kc quantum numberphys.mol.qn;stat.minintJ/A+A/644/A123/ch2ohNew prediction up to 1000GHzrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFreqFrequency of the lineMHzem.freqdoublee_FreqEstimated or experimental errorMHzstat.errordoublelogIntBase 10 logarithm of the integrated intensity in units of nm2.MHzlog(nm**2.MHz)meta.code;spect.line.intensityfloatDOFDegrees of freedom in the rotational partition functionstat.fit.dofintELowLower state energy in wavenumbersphys.energy;phys.atmol.leveldoublegupUpper state degeneracyphys.electron.degenintTagSpecies tag or molecular identifiermeta.codelongN"Upper N quantum numberphys.mol.qnintKa"Upper Ka quantum numberphys.mol.qn;stat.maxintKc"Upper Kc quantum numberphys.mol.qn;stat.maxintv"Upper v quantum numberphys.mol.qn;stat.maxintJ"Upper J quantum numberinstr.det.qe;stat.maxintF1"Upper F1 quantum numberphys.mol.qnintIH"Upper IH quantum numberphys.mol.qnintF"Upper F quantum numberphys.mol.qnintN'Lower N quantum numberphys.mol.qnintKa'Lower Ka quantum numberphys.mol.qn;stat.minintKc'Lower Kc quantum numberphys.mol.qn;stat.minintv'Lower v quantum numberphys.mol.qn;stat.minintJ'Lower J quantum numberinstr.det.qe;stat.minintF1'Lower F1 quantum numberphys.mol.qnintIH'Lower IH quantum numberphys.mol.qnintF'Lower F quantum numberphys.mol.qnint