J/A+A/538/A119ivo://CDS.VizieR/J/A+A/538/A119doi:10.26093/cds/vizier.35380119CDSTercero B.Margules L.Carvajal M.Motiyenko R.A.Huet T.R.,Alekseev E.A.Kleiner I.Guillemin J.C.Mollendal H.Cernicharo J.2015-01-28T12:10:37Z2012-02-10T10:24:10ZCDS support team

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

cds-question@unistra.frinterstellar-mediumspectroscopyAstronomical survey of interstellar molecular clouds needs a previous analysis of the spectra in the microwave and sub-mm energy range of organic molecules in order to be able to identify them. Very accurate spectroscopic constants are obtained in a comprehensive laboratory analysis of rotational spectra. These constants can be used to predict with very high precision the frequencies of transitions that have not been measured in the laboratory. In this work, an experimental study and its theoretical analysis is presented for two ^18^O-methyl formate isotopologues in order to detect for the first time both isotopologues in Orion KL. The experimental spectra of both isotopologues of methyl formate have been recorded in the microwave and sub-mm energy range from 1 to 660GHz. Both spectra have been analysed by using the Rho-Axis Method (RAM) which takes into account the CH3 internal rotation. Spectroscopic constants of both ^18^O-methyl formate have been obtained with high accuracy. Thousands of transitions were assigned and others predicted, which allowed us to detect both species in the IRAM 30m line survey of Orion KL for the first time in the space.2012A&A...538A.119Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/538/A119CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/500/1109 : Rotational spectrum of HCOO^13^CH_3_ (Carvajal+, 2009)J/ApJ/714/1120 : Rotational spectrum and DCOOCH_3_ in Orion (Margules+, 2010)J/ApJS/190/315 : Rotational spectrum of H^13^COOCH_3_ (Carvajal+, 2010)J/A+A/538/A51 : Rotational spectrum of CH_3_CH(NH_2_)CN (Mollendal+, 2011)J/A+A/568/A58 : HCOO^13^CH_3_ rotational spectrum (Haykal+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/538/A119https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/538/A119http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/538/A119https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/538/A119https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/538/A119http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/538/A119GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/538/A119/tables1*Data for ^18^O-methyl formate (HCO^18^OCH_3_) microwave transitions from vt=0 torsional state included in the fit with parameters of Table 4recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLNum[1/123367] Line number (1)meta.idintvt'[0] upper torsional quantum number (2)phys.atmol.qn;stat.maxintJ'[1/63] upper total angular momentum (2)phys.angMomentum;stat.maxintKa'[-34/31] upper Ka rotational quantum number (2)phys.atmol.qn;phys.mol.rotation;stat.maxintKc'[0/63] upper Kc rotational quantum number (2)meta.noteintp'[+-] upper parity (2)phys.atmol.paritycharvt"[0] lower torsional quantum number (2)phys.atmol.qn;stat.minintJ"[1/63] lower total angular momentum (2)phys.angMomentum;stat.minintKa"[-34/31] lower Ka rotational quantum number (2)phys.atmol.qn;phys.mol.rotation;stat.minintKc"[0/63] lower Kc rotational quantum number (2)phys.atmol.qn;phys.mol.rotation;stat.minintp"[+-] lower parity (2)phys.atmol.paritycharoFreq[1630/660000]? Observed frequencyMHzem.freqdoublenullablee_oFreq? Uncertainty in oFreqMHzstat.errorfloatnullablecFreq[1000/660000] Calculated frequencyMHzem.freqdoublee_cFreqUncertainty in cFreqMHzstat.errorfloatLstrLine strength; see text for detailsD**2spect.line.intensityfloatElowLower state energy (3)cm**-1phys.energydoubleJ/A+A/538/A119/tables2*Data for ^18^O-methyl formate (HC^18^OOCH_3_) microwave transitions from vt=0 state included in the fit with parameters of Table 5recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLNum[1/123367] Line number (1)meta.idintvt'[0] upper torsional quantum number (2)phys.atmol.qn;stat.maxintJ'[1/63] upper total angular momentum (2)phys.angMomentum;stat.maxintKa'[-34/31] upper Ka rotational quantum number (2)phys.atmol.qn;phys.mol.rotation;stat.maxintKc'[0/63] upper Kc rotational quantum number (2)meta.noteintp'[+-] upper parity (2)phys.atmol.paritycharvt"[0] lower torsional quantum number (2)phys.atmol.qn;stat.minintJ"[1/63] lower total angular momentum (2)phys.angMomentum;stat.minintKa"[-34/31] lower Ka rotational quantum number (2)phys.atmol.qn;phys.mol.rotation;stat.minintKc"[0/63] lower Kc rotational quantum number (2)phys.atmol.qn;phys.mol.rotation;stat.minintp"[+-] lower parity (2)phys.atmol.paritycharoFreq[1630/660000]? Observed frequencyMHzem.freqdoublenullablee_oFreq? Uncertainty in oFreqMHzstat.errorfloatnullablecFreq[1000/660000] Calculated frequencyMHzem.freqdoublee_cFreqUncertainty in cFreqMHzstat.errorfloatLstrLine strength; see text for detailsD**2spect.line.intensityfloatElowLower state energy (3)cm**-1phys.energydouble