J/A+A/376/356ivo://CDS.VizieR/J/A+A/376/356doi:10.26093/cds/vizier.33760356CDSChandra S.Sharma A.K.2001-09-09T15:14:16Z2001-09-09T15:14:10ZCDS support team

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

cds-question@unistra.fratomic-physicsA number of diatomic molecules have been found in vibrationally excited states in several cosmic objects. The molecules in vibrationally excited states provide valuable information about the physical conditions prevailing near star forming regions and in circumstellar envelopes of late-type stars. To analyze the spectrum of such molecules, some of the important parameters required are the collisional rate coefficients for vib-rotational transitions in the molecule. Currently, knowledge of collisional rate coefficients is very poor. Here, we discuss a method for calculating the collisional rate coefficients for vib-rotational transitions in a diatomic molecule, where the colliding partner H_2_ is considered as a structureless particle. This method is quite good for high temperatures (usually found in star-forming regions and in circumstellar envelopes of late-type stars), but may be questioned for low temperatures. As an example, calculations for the CS molecule at 500K for three vibrational states are presented.2001A&A...376..356Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/376/356CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+AS/114/175 : Einstein A-coefficients in CS transitions (Chandra+ 1995)J/A+AS/117/557 : Einstein coefficients for CO transitions (Chandra+ 1996)J/A+AS/131/137 : Einstein A-Coefficients in SiC2 transitions (Chandra+ 1998)J/A+AS/142/113 : C3H2 and SiC2 collisional rates (Chandra+, 2000)J/A+A/376/333 : Einstein A-coefficients for C_3_H_4_ (Sharma+, 2001)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/376/356https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/376/356http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/376/356https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/376/356https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/376/356http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/376/356GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/376/356/table1Energy, statistical weight, vibrational quantum number, and rotational quantum number of energy levelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoSerial numbermeta.idintEEnergycm**-1phys.energy;phys.mol.vibrationdoubleSWeigthStatistical weightstat.weight;phys.atmolintvVibrational quantum number of energy levelphys.atmol.qnintJRotational quantum number of energy levelphys.atmol.qnintJ/A+A/376/356/table3Collisional rate coefficients for the transition from the upper to the lower leveluUpper levelmeta.idintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintvuVibrational quantum number of upper level (1)phys.atmol.qnintjuRotational quantum number of upper level (1)phys.atmol.qnintvlVibrational quantum number of lower level (1)phys.atmol.qnintjlRotational quantum number of lower level (1)phys.atmol.qnintRateCollisional rate coefficient from u to lcm**3.s**-1arith.rate;phys.atmol.collisionaldoublelLower levelmeta.idint