J/MNRAS/520/4089ivo://CDS.VizieR/J/MNRAS/520/4089doi:10.26093/cds/vizier.75204089CDSZou L.Guillemin J.-C.Belloche A.Jorgensen J.K.Margules L.,Motiyenko R.A.Groner P.2024-11-06T20:34:42Z2023-03-01T07:19:55ZCDS support team

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

cds-question@unistra.fratomic-physicsspectroscopyUp to date, only six imines have been detected in the interstellar medium. The 3-carbon imine, 2-propanimine ((CH_3_)_2_C=NH), is predicted to be the structural isomer with the lowest energy in the C_3_H_7_N group, and appears to be a good candidate for astronomical searches. Unexpectedly, no microwave or millimeter wave spectrum is available for 2-propanimine. In this work, we provide the first high-resolution millimeter wave spectrum of 2-propanimine and its analysis. With the guide of this laboratory measurement, we aim to search for 2-propanimine in two molecule-rich sources Sgr B2(N) and IRAS 16293-2422 using observations from the Atacama Large Millimeter/submillimeter Array (ALMA). Starting from a synthesized sample, we measured the spectrum of 2-propanimine from 50 to 500GHz, and the ground state lines are successfully assigned and fitted using XIAM and ERHAM programs with the aid of theoretical calculations. The barriers to internal rotation of the two CH3 tops are determined to be 531.956(64)cm^-1^ and 465.013(26)cm^-1^ by XIAM. These data are able to provide reliable prediction of transition frequencies for astronomical search. Although a few line matches exist, no confirmed detection of 2-propanimine has been found in the hot molecular core Sgr B2(N1S) and the Class 0 protostar IRAS 16293B. Upper-limits of its column density have been derived, and indicate that 2-propanimine is at least 18 times less abundant than methanimine in Sgr B2(N1S), and is at most 50-83 per cent of methanimine in IRAS 16293B.2023MNRAS.520.4089Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/520/4089CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/853/139 : 1-(Z)-1-propanimine rotational transitions (Sil+, 2018)J/A+A/663/A132 : 1-propanimine measured freq. and residuals (Margules+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/520/4089https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/520/4089http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/520/4089https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/520/4089https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/520/4089http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/520/4089GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/MNRAS/520/4089/table12-propanimine measured frequencyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ''Quantum number J of the upper statephys.atmol.qnintKa''Quantum number Ka of the upper statephys.atmol.qnintKc''Quantum number Kc of the upper statephys.atmol.qnints1Quantum number sigma_1phys.atmol.qnintJ'Quantum number J of the lower statephys.atmol.configurationintKa'Quantum number Ka of the lower statephys.atmol.qnintKc'Quantum number Kc of the lower statephys.atmol.qnints2Quantum number sigma_2phys.atmol.qnintFreqLine frequency observedMHzem.freq;spect.linedoublee_FreqLine frequency uncertaintyMHzstat.errorfloatRelIntRelative intensity for blended lines (1)MHzspect.line.intensity;arith.ratiofloatDiffFrequency difference (obs - calc)MHzstat.fit.residualdoubleJ/MNRAS/520/4089/table42-propanimine prediction up to 1 THzrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFreqFrequency of the line (1)MHzem.freqdoublee_FreqEstimated errorMHzstat.errordoublelogIntBase 10 log of the integrated intensity (3)log(nm**2.MHz)spect.line.intensitydoubleDRDegrees of freedomstat.fit.dofintEloLower state energycm**-1phys.energy;phys.atmol.leveldoubleGupUpper state degeneracy (3)phys.electron.degenintTAGSpecies tagmeta.noteintQNFMTQuantum number (QN) format identifier (2)phys.atmol.qnintJ''QN J of the upper statephys.atmol.qnintKa''QN Ka of the upper statephys.atmol.qnintKc''QN Kc of the upper statephys.atmol.qnints1QN sigma_1phys.atmol.qnintJ'QN J of the lower statephys.atmol.configurationintKa'QN Ka of the lower statephys.atmol.qnintKc'QN Kc of the lower statephys.atmol.qnints2QN sigma_2phys.atmol.qnint