J/ApJ/818/120ivo://CDS.VizieR/J/ApJ/818/120doi:10.26093/cds/vizier.18180120CDSLiu X.Shemansky D.E.Yoshii J.Johnson P.V.Malone C.P.Ajello J.M.2017-01-23T22:00:00Z2016-05-27T13:45:42ZCDS support team

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

cds-question@unistra.fratomic-physicsElectron-impact excitation of H_2_ triplet states plays an important role in the heating of outer planet upper thermospheres. The d^3^{Pi}_u_ state is the third ungerade triplet state, and the d^3^{Pi}_u_-a^3^{Sigma}_g_^+^ emission is the largest cascade channel for the a^3^{Sigma}_g_^+^ state. Accurate energies of the d^3^{Pi}_u_^-^(v, J) levels are calculated from an ab initio potential energy curve. Radiative lifetimes of the d^3^{Pi}_u_(v,J) levels are obtained by an accurate evaluation of the d^3^{Pi}_u_-a^3^{Sigma}_g_^+^ transition probabilities. The emission yields are determined from experimental lifetimes and calculated radiative lifetimes and are further verified by comparing experimental and synthetic d^3^{Pi}_u_-a^3^{Sigma}_g_^+^ spectra at 20eV impact energy. Spectral analysis revealed that multipolar components beyond the dipolar term are required to model the X^1^{Sigma}_g_^+^-d^3^{Pi}_u_ excitation, and significant cascade excitation occurs at the d^3^{Pi}_u_ (v=0,1) levels. Kinetic energy (E_k_) distributions of H atoms produced via predissociation of the ^3^{Pi}_u_ state and the d^3^{Pi}_u_-a^3^{Sigma}_g_^+^-b^3^{Sigma}_u_^+^ cascade dissociative emission are obtained. Predissociation of the d^3^{Pi}_u_ state produces H atoms with an average E_k_ of 2.3+/-0.4 eV/atom, while the E_k_distribution of the d^3^{Pi}_u_-a^3^{Sigma}_g_^+^-b^3^{Sigma}_u_^+^ channel is similar to that of the X^1^{Sigma}_g_^+^-a^3^{Sigma}_g_^+^-b^3^{Sigma}_u_^+^ channel and produces H(1s) atoms with an average E_k_ of 1.15+/-0.05eV/atom. On average, each H_2_ excited to the d^3^{Pi}_u_ state in an H_2_-dominated atmosphere deposits 3.3+/-0.4eV into the atmosphere, while each H_2_directly excited to the a^3^{Sigma}_g_^+^ state gives 2.2-2.3eV to the atmosphere. The spectral distribution of the calculated a^3^{Sigma}_g_^+^-b^3^{Sigma}_u_^+^ continuum emission due to the X^1^{Sigma}_g_^+^-d^3^{Pi}_u_ excitation is significantly different from that of direct a^3^{Sigma}_g_^+^ excitation.2016ApJ...818..120Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/818/120CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/550/A12 : NGC253 near-infrared H_2_ emission (Rosenberg+, 2013)J/MNRAS/418/1994 : GM 2-4 H_2_ emission-line objects (Khanzadyan+, 2011)J/ApJ/711/1236 : Equivalent width of H_2_ from FUSE (Jensen+, 2010)J/A+A/474/941 : Spectroscopy of H_2_ towards HH91A (Gredel+, 2007)J/ApJS/165/256 : Fluorescent H_2_ emission from T Tauri stars (Herczeg+, 2006)J/A+AS/141/297 : H_2_ total transition probability (Abgrall+, 2000)http://www.nist.gov/pml/data/hdel : NIST energy levels of Hydrogen & Deuteriumhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/818/120https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/818/120http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/818/120https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/818/120https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/818/120http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/818/120GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/818/120/table4Adiabatic excitation energies and vibrational overlap integrals of the X^1^{Sigma}_g_^+^(v_m_,J_m_)-d^3^{Pi}_u_(v_n_,J_n_) transitionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintvn[0/20] Upper vibrational quantum numberphys.mol.qnintJn[1/24] Upper rotational quantum numberphys.mol.qnintvm[0/1] Lower vibrational quantum numberphys.mol.qnintJm[0/20] Lower rotational quantum numberphys.mol.qnintEmn[96234/133610] Adiabatic excitation energycm**-1phys.atmol.excitationdouble<Int>[-0.6/0.7] Vibrational overlap integral (1)phys.mol.qndoubleJ/ApJ/818/120/table5Adiabatic energies, transition frequencies, transition probabilities, and Franck-Condon factors of the H_2_ d^3^{Pi}_u_-a^3^{Sigma}_g^+^ band systemrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintv1[0/20] Upper vibrational quantum numberphys.mol.qnintJ1[0/21] Upper rotational quantum numberphys.mol.qnintv0[0/20] Lower vibrational quantum numberphys.mol.qnintJ0[0/20] Lower rotational quantum numberphys.mol.qnintEnergy[111754.5/133834] Adiabatic energy of the upper levelcm**-1phys.energy;phys.atmol.leveldoubleFreq[-6620/38533.4] Transition frequency (1)cm**-1em.freq;phys.atmol.transitiondoubleATransition probability (2)s**-1phys.atmol.transProbdoubleFCF[0/0.96] Franck-Condon factor (3)phys.atmoldouble