J/MNRAS/399/425ivo://CDS.VizieR/J/MNRAS/399/425doi:10.26093/cds/vizier.73990425CDSMaret S.Faure A.Scifoni E.Wiesenfeld L.2024-07-09T20:16:02Z2009-12-29T14:10:48ZCDS support team

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

cds-question@unistra.fratomic-physicsAmmonia inversion lines are often used as probes of the physical conditions in the dense ISM. The excitation temperature between the first two para metastable (rotational) levels is an excellent probe of the gas kinetic temperature. However, the calibration of this ammonia thermometer depends on the accuracy of the collisional rates with H2. Here we present new collisional rates for ortho-NH3 and para-NH3 colliding with para-H2 (J=0) and we investigate the effects of these new rates on the excitation of ammonia. Scattering calculations employ a new, high accuracy, potential energy surface computed at the coupled-cluster CCSD(T) level with a basis set extrapolation procedure. Rates are obtained for all transitions involving ammonia levels with J<=3 and for kinetic temperatures in the range 5-100K. We find that the calibration curve of the ammonia thermometer -- which relates the observed excitation temperature between the first two para metastable levels to the gas kinetic temperature -- does not change significantly when these new rates are used. Thus, the calibration of ammonia thermometer appears to be robust. Effects of the new rates on the excitation temperature of inversion and rotation-inversion transitions are also found to be small.2009MNRAS.399..425Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/399/425CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/472/1029 : (De)excitation rates of H2O by H2 (Faure+, 2007)J/A+A/492/257 : Collisional excitation of water in warm media (Faure+, 2008)J/A+A/493/687 : Rotational excitation of formaldehyde by H2 (Faure+, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/399/425https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/399/425http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/399/425https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/399/425https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/399/425http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/399/425GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/MNRAS/399/425/levelsEnergy levels of ortho- and para-NH3recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_LevelSimbad column added by the CDSphys.atmol.configurationcharLevel[1,10] level numbermeta.idintElevel energycm**-1phys.energy;phys.atmol.leveldoubleFstatistical weightphys.atmol.sWeightfloatNquantum numbersphys.atmol.qncharJ/MNRAS/399/425/nh3_h2De-excitation rates of ortho- and para-NH3 in collision with para-H_2_recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_TransSimbad column added by the CDSphys.atmol.configurationcharTrans[1,45] Transition numbermeta.idinti[2,10] Initial levelphys.atmol.initial;phys.atmol.levelintk5Rate coefficient at 5Kcm**3.s**-1arith.ratedoublek10Rate coefficient at 10Kcm**3.s**-1arith.ratedoublek15Rate coefficient at 15Kcm**3.s**-1arith.ratedoublek20Rate coefficient at 20Kcm**3.s**-1arith.ratedoublek25Rate coefficient at 25Kcm**3.s**-1arith.ratedoublek30Rate coefficient at 30Kcm**3.s**-1arith.ratedoublek35Rate coefficient at 35Kcm**3.s**-1arith.ratedoublek40Rate coefficient at 40Kcm**3.s**-1arith.ratedoublek45Rate coefficient at 45Kcm**3.s**-1arith.ratedoublek50Rate coefficient at 50Kcm**3.s**-1arith.ratedoublek55Rate coefficient at 55Kcm**3.s**-1arith.ratedoublek60Rate coefficient at 60Kcm**3.s**-1arith.ratedoublek65Rate coefficient at 65Kcm**3.s**-1arith.ratedoublek70Rate coefficient at 70Kcm**3.s**-1arith.ratedoublek75Rate coefficient at 75Kcm**3.s**-1arith.ratedoublek80Rate coefficient at 80Kcm**3.s**-1arith.ratedoublek85Rate coefficient at 85Kcm**3.s**-1arith.ratedoublek90Rate coefficient at 90Kcm**3.s**-1arith.ratedoublek95Rate coefficient at 95Kcm**3.s**-1arith.ratedoublek100Rate coefficient at 100Kcm**3.s**-1arith.ratedoublef[1,10] Final levelphys.atmol.final;phys.atmol.levelint