J/A+A/687/A8ivo://CDS.VizieR/J/A+A/687/A8doi:10.26093/cds/vizier.36870008CDSMueller H.S.P.Coutens A.Jorgensen J.K.Margules L.Motiyenko R.A.,Guillemin J.-C.2024-11-29T20:04:26Z2024-06-24T12:08:49ZCDS support team

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

cds-question@unistra.fratomic-physics3-Hydroxypropenal (HOCHCHCHO) is the lower energy tautomer of malonaldehyde which displays a complex rotationtunneling spectrum. It was detected some- what tentatively toward the solar-type protostellar system IRAS 16293-2422 with ALMA in the framework of the Protostellar Interferometric Line Survey (PILS). Several transitions, however, had large residuals, preventing not only their detection, but also the excitation temperature of the species from being determined unambiguously. We want to extend the existing rotational line list of 3-hydroxypropenal to shed more light on the recent observational results and to facilitate additional radio astronomical searches for this molecule. We recorded and analyzed the rotation-tunneling spectrum of 3-hydroxypropenal in the frequency regions between 150 and 330 GHz and between 400 and 660 GHz. Transitions were searched for in the PILS observations of IRAS 16293-2422. Local thermodynamic equilibrium (LTE) models were carried out and compared to the observations to constrain the excitation temperature. Additional transitions were searched for in other ALMA archival data of the same source to confirm the presence of 3-hydroxypropenal. More than 7500 different spectral lines, corresponding to more than 11500 transitions, were assigned in the course of our investigation with quantum numbers 2<=J<=100, Ka<=59, and Kc<=97, resulting in a greatly improved set of spectroscopic parameters. The comparison between the LTE models and the observations yields an excitation temperature of 125K with a column density N=1.0x10^15^cm^-2^ for this species. We identified seven additional lines of 3-hydroxypropenal that show a good agreement with the model in the ALMA archive data. The calculated rotation-tunneling spectrum of 3-hydroxypropenal has sufficient accuracy for radio astronomical searches. With the solution of the excitation temperature conundrum and the detection of seven more lines, we consider the detection of 3-hydroxypropenal toward IRAS 16293-2422 as secure.2024A&A...687A...8Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/687/A8CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/687/A8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/687/A8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/687/A8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/687/A8https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/687/A8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/687/A8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/687/A8/3-hpTransitions included in the fit of 3-HydroxypropenalrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ'Upper state J quantum numberphys.atmol.configurationintKa'Upper state Ka quantum numberphys.mol.qnintKc'Upper state Kc quantum numberphys.mol.qnintv'Upper state v; 0 = 0^+^; 1 = 0^-^phys.mol.qnintJ"Lower state J quantum numberphys.atmol.configurationintKa"Lower state Ka quantum numberphys.mol.qnintKc"Lower state Kc quantum numberphys.mol.qnintv"Lower state v; 0 = 0^+^; 1 = 0^-^phys.mol.qnintFreqObsObserved transition frequencyMHzem.freqdoublee_FreqObsExperimental uncertaintyMHzstat.errorfloat(O-C)Observed minus calculated frequency (for group of lines if they are at the same frequency)MHzem.freq;stat.fit.omcdoublewb? Weight of the component in group of linesphys.atmol.weightfloatnullableNotesSource of data (reference) (1)meta.notechar