J/A+A/563/A137ivo://CDS.VizieR/J/A+A/563/A137doi:10.26093/cds/vizier.35630137CDSMotiyenko R.A.IlyushinV.V.Drouin B.J.Yu.S.Margules L.2014-09-03T12:40:32Z2014-03-25T07:05:36ZCDS support team

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

cds-question@unistra.fratomic-physicsinterstellar-mediummillimeter-astronomysubmillimeter-astronomyMethylamine (CH_3_NH_2_) is the simplest primary alkylamine and has been detected in the interstellar medium. The molecule is relatively light, with the 50K Boltzmann peak appearing near 800GHz. However, reliable predictions for its rotational spectrum are available only up to 500GHz. Spectroscopic analyses have been complicated by the two large amplitude motions: internal rotation of the methyl top and inversion of the amino group. The aims is to provide reliable predictions of the methylamine ground state rotational spectrum above 500GHz we studied its rotational spectrum in the frequency range from 500 to 2650GHz. The spectra of methylamine were recorded using the spectrometers based on Schottky diode frequency multiplication chains in the Lille laboratory (500-945GHz) and in JPL (1060-2660GHz). The analysis of the rotational spectrum of methylamine in the ground vibrational state was performed on the basis of the group-theoretical high barrier tunneling Hamiltonian developed for methylamine by Ohashi and Hougen. In the recorded spectra we have assigned 1849 new rotational transitions of methylamine. They were fitted together with previously published data to a Hamiltonian model that uses 76 parameters with overall weighted rms deviation of 0.87. On the basis of the new spectroscopic results, predictions of transition frequencies in the frequency range up to 3THz with J<50 and Ka<20 are presented.2014A&A...563A.137Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/563/A137CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/493/565 : Deuterated and ^15^N ethyl cyanides (Margules+, 2009)J/A+A/538/A51 : Rotational spectrum of CH_3_CH(NH_2_)CN (Mollendal+, 2012)J/A+A/538/A119 : Spectrum of ^18^O-methyl formate (HCO18OCH3) (Tercero+ 2012)J/A+A/540/A51 : Submm spectrum of deuterated glycolaldehydes (Bouchez+, 2012)J/A+A/543/A46 : Submillimeter spectrum of HCOOCD_2_H (Coudert+, 2012)J/A+A/543/A135 : New analysis of ^13^C-CH_3_CH_2_CN up to 1THz (Richard+, 2012)J/A+A/544/A82 : Rotational spectroscopy of diisocyanomethane (Motiyenko+, 2012J/A+A/548/A71 : Spectroscopy and ISM detection of formamide (Motiyenko+, 2012)J/A+A/549/A96 : The mm & sub-mm spectra of 13C-glycolaldehydes (Haykal+, 2013)J/A+A/549/A128 : Singly deuterated isotopologues of formamide (Kutsenko+, 2013)J/A+A/552/A117 : Mono-deuterated dimethyl ether (Richard+, 2013)J/A+A/553/A84 : (Sub)mm spectrum of deuterated methyl cyanides (Nguyen+, 2013)J/A+A/559/A44 : Rotational spectrum of MAAN (CH_2_NCH_2_CH) (Motiyenko+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/563/A137https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/563/A137http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/563/A137https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/563/A137https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/563/A137http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/563/A137GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapRadiodefaultJ/A+A/563/A137/table2Measured rotational transitions of methylamine (CH_3_NH_2_) in the ground vibrational staterecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1[1/44] Upper J quantum numberinstr.det.qe;stat.maxintKa1[0/19] Upper Ka quantum numberphys.atmol.qn;stat.maxintG1Upper symmetry species {Gamma} (G1)phys.atmol.configurationcharJ0[0/44] Lower J quantum numberinstr.det.qe;stat.minintKa0[0/18] Lower Ka quantum numberphys.atmol.qn;stat.minintG0Lower symmetry species {Gamma} (G1)phys.atmol.configurationcharFreq[5/2661539] Observed transition frequencyMHzem.freqdoubleError[-0.001/0.5] Uncertainty of measurementsMHzstat.errordoubleO-C[-1/1] Residuals of the fitMHzstat.fit.residual;stat.fit.param;meta.modelleddoubleRef[1/11] Reference (1)meta.ref;pos.frameintNNumber of transitions observed or computed having these J0/J1 Ka0/Ka1 G0/G1 quantum numbersmeta.numberintnullableJ/A+A/563/A137/table3Predicted transitions of methylamine in the ground vibrational staterecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ1[1/50] Upper J quantum numberinstr.det.qe;stat.maxintKa1[0/20] Upper Ka quantum numberphys.atmol.qn;stat.maxintG1Upper symmetry species {Gamma} (G1)phys.atmol.configurationcharF1[0/51] Upper F quantum numberphys.atmol.qnintJ0[0/50] Lower J quantum numberinstr.det.qe;stat.minintKa0[0/20] Lower Ka quantum numberphys.atmol.qn;stat.minintG0Lower symmetry {Gamma}0 specie (G1)phys.atmol.configurationcharF0[0/51] Lower F quantum numberphys.atmol.qnintFreq[1019/2999600] Calculated transition frequencyMHzem.freqdoubleError[0.0005/0.9995] Calculated uncertaintyMHzstat.error;meta.modelledfloatmu2S[0/49] Calculated line strengthD**2spect.line.intensityfloatWst[1/3] Statistical weightstat.weightintE0[0/2508] Energy of the lower statecm**-1phys.energy;phys.atmol.leveldoubleONumber of transitions observed having these J0/J1 Ka0/Ka1 G0/G1 quantum numbersmeta.numberintnullable