J/A+A/612/A56ivo://CDS.VizieR/J/A+A/612/A56doi:10.26093/cds/vizier.36120056CDSPrudenzano D.Laas J.Bizzocchi L.Lattanzi V.Endres C.,Giuliano B.M.Spezzano S.Palumbo M.E.Caselli P.2018-05-16T08:39:07Z2018-04-20T07:28:24ZCDS support team

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

cds-question@unistra.fratomic-physicsradio-astronomyA better understanding of sulphur chemistry is needed to solve the interstellar sulphur depletion problem. A way to achieve this goal is to study new S-bearing molecules in the laboratory, obtaining accurate rest frequencies for an astronomical search. We focus on dithioformic acid, HCSSH, which is the sulphur analogue of formic acid. The aim of this study is to provide an accurate line list of the two HCSSH trans and cis isomers in their electronic ground state and a comprehensive centrifugal distortion analysis with an extension of measurements in the millimetre and submillimetre range. We studied the two isomers in the laboratory using an absorption spectrometer employing the frequency-modulation technique. The molecules were produced directly within a free-space cell by glow discharge of a gas mixture. We measured lines belonging to the electronic ground state up to 478GHz, with a total number of 204 and 139 new rotational transitions, respectively, for trans and cis isomers. The final dataset also includes lines in the centimetre range available from literature. The extension of the measurements in the mm and submm range lead to an accurate set of rotational and centrifugal distortion parameters. This allows us to predict frequencies with estimated uncertainties as low as 5kHz at 1mm wavelength. Hence, the new dataset provided by this study can be used for astronomical search.2018A&A...612A..56Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/612/A56CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/602/A34 : HOCO+ and DOCO+ rest frequencies (Bizzocchi+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/612/A56https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/612/A56http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/612/A56https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/612/A56https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/612/A56http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/612/A56GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapRadiodefaultJ/A+A/612/A56/table4Predicted rest frequencies, estimated accuracies, lines strenghts, energy of the upper states and Einstein A coefficients for the ground vibrational state of cis-HCSSHrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ'Upper state Jmeta.noteintKa'Upper state Kaphys.mol.qnintKc'Upper state Kcphys.mol.qnintJLower state Jphys.atmol.qnintKaLower state Kaphys.mol.qnintKcLower state Kcphys.mol.qnintRestFreqRest frequencyMHzem.freqdoublee_RestFreqEstimated error on rest frequencykHzstat.errorfloatLineStrtransition strength (Debye^2^)D**2spect.line.strength;phys.atmol.transitiondoubleEupperUpper state energycm**-1phys.energy;phys.atmol.levelfloatAEinstein's A coefficients**-1phys.atmol.transProbdoubleJ/A+A/612/A56/table3Predicted rest frequencies, estimated accuracies, lines strenghts, energy of the upper states and Einstein A coefficients for the ground vibrational state of trans-HCSSHrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ'Upper state Jmeta.noteintKa'Upper state Kaphys.mol.qnintKc'Upper state Kcphys.mol.qnintJLower state Jphys.atmol.qnintKaLower state Kaphys.mol.qnintKcLower state Kcphys.mol.qnintRestFreqRest frequencyMHzem.freqdoublee_RestFreqEstimated error on rest frequencykHzstat.errorfloatLineStrtransition strength (Debye^2^)D**2spect.line.strength;phys.atmol.transitiondoubleEupperUpper state energycm**-1phys.energy;phys.atmol.levelfloatAEinstein's A coefficients**-1phys.atmol.transProbdoubleJ/A+A/612/A56/table1Assignments, measured line positions and least-squares residuals for the analysed transitions of trans-HCSSHrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ'Upper state Jmeta.noteintKa'Upper state Kaphys.mol.qnintKc'? Upper state Kc (1)phys.mol.qnintnullableJLower state Jphys.atmol.qnintKaLower state Kaphys.mol.qnintKc? Lower state Kc (1)phys.mol.qnintnullableObsMeasured line positionMHzem.freqdoubleO-CLeast-squares residualMHzstat.fit.residualdoubleuncAssumed uncertaintyMHzstat.errorfloatRefReference (2)meta.ref;pos.framecharJ/A+A/612/A56/table2Assignments, measured line positions and least-squares residuals for the analysed transitions of cis-HCSSHKc? Lower state Kc (1)phys.mol.qnintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ'Upper state Jmeta.noteintKa'Upper state Kaphys.mol.qnintKc'? Upper state Kc (1)phys.mol.qnintnullableJLower state Jphys.atmol.qnintKaLower state Kaphys.mol.qnintObsMeasured line positionMHzem.freqdoubleO-CLeast-squares residualMHzstat.fit.residualdoubleuncAssumed uncertaintyMHzstat.errorfloatRefReference (2)meta.ref;pos.framechar