J/ApJS/211/28ivo://CDS.VizieR/J/ApJS/211/28doi:10.26093/cds/vizier.22110028CDSHeays A.N.Ajello J.M.Aguilar A.Lewis B.R.Gibson S.T.2014-06-12T12:36:34Z2014-05-26T07:59:04ZCDS support team

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

cds-question@unistra.fratomic-physicsspectroscopyultraviolet-astronomyWe have analyzed high-resolution (FWHM=0.2{AA}) extreme-ultraviolet (EUV, 800-1350{AA}) laboratory emission spectra of molecular nitrogen excited by an electron impact at 20 and 100eV under (mostly) optically thin, single-scattering experimental conditions. A total of 491 emission features were observed from N_2_ electronic-vibrational transitions and atomic N I and N II multiplets and their emission cross sections were measured. Molecular emission was observed at vibrationally excited ground-state levels as high as v"=17, from the a^1^{Pi}_g_, b^1^{Pi}_u_, and b'^1^{Sigma}_u_^+^ excited valence states and the Rydberg series c'_n+1_^1^{Sigma}_u_^+^, c_n_^1^{Pi}_u_, and o_n_^1^{Pi}_u_ for n between 3 and 9. The frequently blended molecular emission bands were disentangled with the aid of a sophisticated and predictive quantum-mechanical model of excited states that includes the strong coupling between valence and Rydberg electronic states and the effects of predissociation. Improved model parameters describing electronic transition moments were obtained from the experiment and allowed for a reliable prediction of the vibrationally summed electronic emission cross section, including an extrapolation to unobserved emission bands and those that are optically thick in the experimental spectra. Vibrationally dependent electronic excitation functions were inferred from a comparison of emission features following 20 and 100eV electron-impact collisional excitation. The electron-impact-induced fluorescence measurements are compared with Cassini Ultraviolet Imaging Spectrograph observations of emissions from Titan's upper atmosphere.2014ApJS..211...28Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/211/28CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/559/A114 : O3N2 and N2 abundance indicators revisited (Marino+, 2013)J/A+A/439/387 : Absolute photoionization cross sections (Bizau+, 2005)J/A+AS/128/361 : Vacuum ultraviolet emission band systems of N2 (Roncin+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/211/28https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/211/28http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/211/28https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/211/28https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/211/28http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/211/28GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVdefaultJ/ApJS/211/28/table1Experimental resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintLineAssignmentmeta.id;phys.atmol.transitioncharlambda[806/1347] Peak wavelength; in Angstroms0.1nmem.wl;stat.maxdoubleCS20[0.01/51.6]? Emission cross section at 20eV1e-20cm**2meta.id.cross;phys.atmol.crossSectionfloatnullablee_CS20[0.009/0.9]? One sigma uncertainty in CS201e-20cm**2stat.errorfloatnullablen_CS20Note(s) on CS20 (1)meta.notecharCS100[0.05/178]? Emission cross section at 100eV1e-20cm**2meta.id.cross;phys.atmol.crossSectionfloatnullablee_CS100[0.02/4]? One sigma uncertainty in CS1001e-20cm**2stat.errorfloatnullablen_CS100Note(s) on CS100 (1)meta.notechar