J/A+A/609/A121ivo://CDS.VizieR/J/A+A/609/A121doi:10.26093/cds/vizier.36090121CDSMelosso M.Melli A.Puzzarini C.Codella C.Spada L.Dore L.,Degli Esposti C.Lefloch B.Bachiller R.Ceccarelli C.Cernicharo J.,Barone V.2018-02-08T11:27:52Z2018-02-02T08:57:23ZCDS support team

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

cds-question@unistra.fratomic-physicsinterstellar-mediumC-cyanomethanimine (HNCHCN), existing in the two Z and E isomeric forms, is a key prebiotic molecule, but, so far, only the E isomer has been detected towards the massive star forming region Sagittarius B2(N) using transitions in the radio wavelength domain. With the aim of detecting HNCHCN in Sun-like star-forming regions, the laboratory investigation of its rotational spectrum has been extended to the milllimeter-/submillimeter-wave (mm-/submm-) spectral window where several unbiased spectral surveys have been already obtained. High-resolution laboratory measurements of the rotational spectrum of C-cyanomethanimine were carried out in the 100-420GHz range using a frequency-modulation absorption spectrometer. The C-cyanomethanimine spectral features were then searched for in the mm-wave range using the high-sensitivity and unbiased spectral surveys obtained with the IRAM 30-m antenna in the ASAI context, the earliest stages of star formation from starless to evolved Class I objects being sampled. For both the Z and E isomers, the spectroscopic work has led to an improved and extended knowledge of the spectroscopic parameters, thus providing accurate predictions of the rotational signatures up to ~700GHz. So far, no C-cyanomethanimine emission has been detected towards the ASAI targets, and upper limits on the column density of 10^11^-10^12^cm^-2^ could only be derived. Consequently, the C-cyanomethanimine abundances have to be less than a few 10^-10^ for starless and hot-corinos. A less stringent constraint, <=10^-9^, is obtained for shocks sites. The combination of the upper limits on the abundances of C-cyanomethanimine together with accurate laboratory frequencies up to ~700GHz poses the basis for future higher sensitivity searches around Sun-like star forming regions. For compact (typically less than 1 arcsec) and chemically enriched sources such as hot-corinos, the use of interferometers as NOEMA and ALMA in their extended configurations are clearly needed.2018A&A...609A.121Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/609/A121CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/562/A56 : Cyanomethyl anion & its deuterated derivatives (Majumdar+ 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/609/A121https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/609/A121http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/609/A121https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/609/A121https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/609/A121http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/609/A121GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/609/A121/table2Measured rotational transitions and residuals from the fit for the two isomers of C-cyanomethanimine in the ground stateF? Lower F quantum number (1)phys.atmol.qnintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSpeciesIsomerphys.atmol.elementcharN'Upper N quantum numberphys.atmol.qnintKa'Upper Ka quantum numberphys.atmol.qn;stat.maxintKc'Upper Kc quantum numberphys.atmol.qn;stat.maxintI'? Upper I quantum number (1)phys.atmol.qnintnullableF'? Upper F quantum number (1)phys.atmol.qnintnullableNLower N quantum numberphys.atmol.qnintKaLower Ka quantum numberphys.atmol.qn;stat.minintKcLower Kc quantum numberphys.atmol.qn;stat.minintI? Lower I quantum number (1)phys.atmol.qnintnullableFreqObserved frequencyMHzem.freqdoubleUncExperimental uncertaintyMHzstat.errorfloatO-CObserved minus calculated frequenciesMHzstat.fit.residualfloatWeight? Relative weight (2)stat.weight;phys.atmol.weightfloatnullableRefReference (3)meta.ref;pos.framechar