J/A+A/466/255ivo://CDS.VizieR/J/A+A/466/255doi:10.26093/cds/vizier.34660255CDSDemyk K.Maeder H.Tercero B.Cernicharo J.Demaison J.Magules L.,Wegner M.Keipert S.Sheng M.2017-10-12T12:59:44Z2007-06-17T08:37:56ZCDS support team

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

cds-question@unistra.fratomic-physicsAstronomical spectra of hot molecular clouds in the wavelength range from centimeter to submillimeter show a huge number of rotational lines due to the emission of complex organic molecules, and a large fraction of these lines are unidentified. The assignment of these unidentified lines to new molecules, to known molecules in excited states, or to their isotopologues requires a good knowledge of the spectroscopic parameters of these molecules. We present the experimental study of the spectroscopic properties of ^13^C-substituted ethyl cyanide ^13^CH3CH2CN, CH3^13^CH2CN, and CH3CH2^13^CN. The rotational spectra of the three species in the ground state have been measured in the frequency ranges from 5 to 26GHz using waveguide Fourier transform spectrometers and from 160 to 360GHz using a source-modulated spectrometer employing backward-wave oscillators (BWOs). A new accurate set of spectroscopic constants has been determined for each isotopic species. This permits prediction of the position of rotational lines that are best suited for detection with an accuracy of a few hundreds of kHz. The three isotopologues have been detected in an Orion IRc2 IRAM survey via several hundred of lines, illustrating that many "unidentified" bands are definitely due to isotopologues of known molecules.2007A&A...466..255Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/466/255CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/466/255https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/466/255http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/466/255https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/466/255https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/466/255http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/466/255GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/466/255/TransAll transitions of CH_3_CH_2_CNrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIsoSimbad column added by the CDSmeta.id;phys.molcharJ0J value of the lower statephys.atmol.qnintKa0Ka value of the lower statephys.atmol.qnintKc0Kc value of the lower statephys.atmol.qnintJ1J value of the upper statephys.atmol.qnintKa1Ka value of the upper statephys.atmol.qnintKc1Kc value of the upper statephys.atmol.qnintFreqCalculated frequencyMHzem.freq;meta.modelleddoubleindexede_FreqError on the calculated frequencyMHzstat.errorfloatSLine strengthspect.line.intensityfloatDipole[A/B] Type of the transitionmeta.notecharE0Energy of the lower statecm**-1phys.energy;phys.atmol.levelfloat