Laboratory Study of the Cameron Bands, the First Negative Bands, and Fourth Positive Bands in the Middle Ultraviolet 180–280 nm by Electron Impact Upon CO
Lee, Rena A.; Ajello, Joseph M.; Malone, Charles P.et al.
2021 • In Journal of Geophysical Research. Planets, 126 (1)
carbon monoxide (CO); cascade; electron impact; emission cross sections; fluorescence lifetimes; MAVEN IUVS; Earth and Planetary Sciences (miscellaneous); Space and Planetary Science
Abstract :
[en] We have analyzed medium-resolution (full width at half maximum, FWHM = 1.2 nm), Middle UltraViolet (MUV; 180–280 nm) laboratory emission spectra of carbon monoxide (CO) excited by electron impact at 15, 20, 40, 50, and 100 eV under single-scattering conditions at 300 K. The MUV emission spectra at 100 eV contain the Cameron Bands (CB) CO(a 3Π → X 1Σ+), the fourth positive group (4PG) CO(A 1Π → X 1Σ+), and the first negative group (1NG) CO+(B 2Σ+ → X 2Σ) from direct excitation and cascading-induced emission of an optically thin CO gas. We have determined vibrational intensities and emission cross sections for these systems, important for modeling UV observations of the atmospheres of Mars and Venus. We have also measured the CB “glow” profile about the electron beam of the long-lived CO (a 3Π) state and determined its average metastable lifetime of 3 ± 1 ms. Optically allowed cascading from a host of triplet states has been found to be the dominant excitation process contributing to the CB emission cross section at 15 eV, most strongly by the d 3Δ and a' 3Σ+ electronic states. We normalized the CB emission cross section at 15 eV electron impact energy by multilinear regression (MLR) analysis to the blended 15 eV MUV spectrum over the spectral range of 180–280 nm, based on the 4PG emission cross section at 15 eV that we have previously measured (Ajello et al., 2019, https://doi.org/10.1029/2018ja026308). We find the CB total emission cross section at 15 eV to be 7.7 × 10−17 cm2.
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Lee, Rena A. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States ; Now at Earth and Planetary Sciences, School of Ocean and Earth Sciences and Technology, University of Hawaii, Honolulu, United States
Ajello, Joseph M. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States
Malone, Charles P. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, United States
Evans, J. Scott ; Computational Physics Inc., Springfield, United States
Veibell, Victoir ; Computational Physics Inc., Springfield, United States
Holsclaw, Gregory M. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States
McClintock, William E. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States
Hoskins, Alan C.; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States
Jain, Sonal ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO)
Schneider, Nicholas M. ; Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, United States
Language :
English
Title :
Laboratory Study of the Cameron Bands, the First Negative Bands, and Fourth Positive Bands in the Middle Ultraviolet 180–280 nm by Electron Impact Upon CO
This work was primarily performed at the Laboratory for Atmospheric and Space Physics (LASP), University of Colorado (CU) Boulder, and the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), under a contract with the National Aeronautics and Space Administration (NASA). We gratefully acknowledge financial support through NASA's Solar System Workings (SSW), Cassini Data Analysis Program (CDAP), the Heliophysics H-TIDeS and Geospace Science programs, Mars Data Analysis Program (MDAP), and the National Science Foundation (NSF) GEO-AGS Aeronomy program. J.-C. G?rard is supported by the PRODEX program managed by the European Space Agency (ESA) with help from the Belgian Federal Science Policy Office (BELSPO). R. A. Lee thanks the NSF Research Experience for Undergraduates (REU) program for support. We thank X. Liu for 4PG rovibrational spectral models. We thank Karl Hubbell for technical support and Bruce Jakosky, and the MAVEN team, for usage of the IUVS optical-engineering unit (OEU). U.S. government sponsorship is acknowledged.This work was primarily performed at the Laboratory for Atmospheric and Space Physics (LASP), University of Colorado (CU) Boulder, and the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), under a contract with the National Aeronautics and Space Administration (NASA). We gratefully acknowledge financial support through NASA's Solar System Workings (SSW), Cassini Data Analysis Program (CDAP), the Heliophysics H‐TIDeS and Geospace Science programs, Mars Data Analysis Program (MDAP), and the National Science Foundation (NSF) GEO‐AGS Aeronomy program. J.‐C. Gérard is supported by the PRODEX program managed by the European Space Agency (ESA) with help from the Belgian Federal Science Policy Office (BELSPO). R. A. Lee thanks the NSF Research Experience for Undergraduates (REU) program for support. We thank X. Liu for 4PG rovibrational spectral models. We thank Karl Hubbell for technical support and Bruce Jakosky, and the MAVEN team, for usage of the IUVS optical‐engineering unit (OEU). U.S. government sponsorship is acknowledged.
Ajello, J. M. (1971a). Emission cross sections of CO by electron impact in the interval 1260-5000. The Journal of Chemical Physics, 55, 3158–3168. https://doi.org/10.1063/1.1676563
Ajello, J. M. (1971b). Emission cross sections of CO2 by electron impact in the interval 1260-5000. The Journal of Chemical Physics, 55, 3169–3177. https://doi.org/10.1063/1.1676564
Ajello, J. M., Evans, J. S., Veibell, V., Malone, C. P., Holsclaw, G. M., Hoskins, A. C., et al. (2020). The UV spectrum of the Lyman-Birge-Hopfield band system of N2 induced by cascading from electron impact. Journal of Geophysical Research: Space Physics, 125, e2019JA027546. https://doi.org/10.1029/2019JA027546
Ajello, J. M., Malone, C. P., Evans, J. S., Holsclaw, G. M., Hoskins, A. C., Jain, S. K., et al. (2019). UV study of the fourth positive band system of CO and O | 135.6 nm from electron impact on CO and CO2. Journal of Geophysical Research: Space Physics, 124, 2954–2977. https://doi.org/10.1029/2018JA026308
Ajello, J. M., Malone, C. P., McClintock, W. E., Hoskins, A. C., & Eastes, R. W. (2017). Electron impact measurement of the 100 eV emission cross section and lifetime of the Lyman-Birge-Hopfield band system of N2: Direct excitation and cascading. Journal of Geophysical Research: Space Physics, 122(6), 6776–6790. https://doi.org/10.1002/2017JA024087
Al Matroushi, H., Lootah, F., Holsclaw, G., Deighan, J., Chaffin, M., EMUS, team, et al. (2019). Scientific payload of the Emirates Mars Mission: Emirates Mars Ultraviolet Spectrometer (EMUS) overview. Ninth International Conference on Mars LPI Contribution No. 2089, id. 6073 Pasadena, CA. Retrieved from https://ui.adsabs.harvard.edu/abs/2019LPICo2089.6073A
Avakyan, S. V., Il'in, R. N., Lavrov, V. M., & Ogurtsov, G. N. (1998). Collision processes and excitation of UV emission from planetary atmospheric gases: A handbook of cross sections. India: Gordon and Breach Science Publishers.
Barth, C. A., Hord, C. W., Pearce, J. B., Kelly, K. K., Anderson, G. P., & Stewart, A. I. (1971). Mariner 6 and 7 ultraviolet spectrometer experiment: Upper atmosphere data. Journal of Geophysical Research, 76(10), 2213–2532. https://doi.org/10.1029/JA076i010p02213
Barth, C. A., Hord, C. W., Stewart, A. I., Lane, A. L., Dick, M. L., & Anderson, G. P. (1973). Mariner 9 ultraviolet spectrometer experiment: Seasonal variation of ozone on Mars. Science, 179, 795–796. https://doi.org/10.1126/science.179.4075.795
Barth, C. A., Stewart, A. I., Hord, C. W., & Lane, A. L. (1972). Mariner 9 ultraviolet spectrometer experiment: Mars airglow spectroscopy and variations in Lyman alpha. Icarus, 17, 457–462. https://doi.org/10.1016/0019-1035(72)90011-5
Bertaux, J.-L., Korablev, O., Perrier, S., Quémarais, E., Montmessin, F., Leblanc, F., et al. (2006). SPICAM on Mars Express: Observing modes and overview of UV spectrometer data and scientific results. Journal of Geophysical Research, 111, E10S90. https://doi.org/10.1029/2006JE002690
Bhardwaj, A., & Jain, S. K. (2013). CO Cameron band and UV doublet emissions in the dayglow of Venus: Role of CO in the Cameron band production. Journal of Geophysical Research: Space Physics, 118(6), 3660–3671. https://doi.org/10.1002/jgra.50345
Borst, W. L., & Zipf, E. C. (1971). Lifetimes of metastable CO and N2 molecules. Physical Review A, 3(3), 979–989. https://doi.org/10.1103/PhysRevA.3.979
Chaufray, J.-Y., Bertaux, J. -L., & Leblanc, F. (2012). First observation of the Venus UV dayglow at limb from SPICAV/VEX. Geophysical Research Letters, 39(20), L20201. https://doi.org/10.1029/2012GL053626
Conway, R. R. (1981). Spectroscopy of the Cameron bands in the Mars Airglow. Journal of Geophysical Research, 86(A6), 4767–4775. https://doi.org/10.1029/JA086iA06p04767
Deighan, J., Chaffin, M. S., Chaufray, J.-Y., Stewart, A. I. F., Schneider, N. M., Jain, S. K., et al. (2015). MAVEN IUVS observation of the hot oxygen corona at Mars. Geophysical Research Letters, 42(21), 9009–9014. https://doi.org/10.1002/2015GL065487
Erdman, P. W., & Zipf, E. C. (1983). Electron-impact excitation of the Cameron system (a 3Π → X1 Σ) of CO. Planetary and Space Science, 31(3), 317–321. https://doi.org/10.1016/0032-0633(83)90082-X
Evans, J. S., Stevens, M. H., Lumpe, J. D., Schneider, N. M., Stewart, A. I. F., Deighan, J., et al. (2015). Retrieval of CO2 and N2 in the Martian atmosphere using dayglow observations by IUVS on MAVEN. Geophysical Research Letters, 42(21), 9345–9589. https://doi.org/10.1002/2015GL065489
Feldman, P. D., Burgh, E. B., Durrance, S. T., & Davidsen, A. F. (2000). Far-ultraviolet spectroscopy of Venus and Mars at 4 Å resolution with the Hopkins ultraviolet telescope on Astro-2. The Astrophysical Journal, 538(1), 395–400. https://doi.org/10.1086/309125
Ferlet, R., André, M., Hébrard, G., Lecavelier des Etangs, A., Lemoine, M., Pineau des Forêts, G., et al. (2000). Far ultraviolet spectroscopic Explorer observations of the HD molecule toward HD 73882. The Astrophysical Journal, 538(1), L69–L72. https://doi.org/10.1086/312799
Fox, J. L. (2008). Morphology of the dayside ionosphere of Venus: Implications for ion outflows. Journal of Geophysical Research, 113, E11001. https://doi.org/10.1029/2008JE003182
Furlong, J. M., & Newell, W. R. (1996). Total cross section measurement for the metastable a 3Π state in CO. Journal of Physics B: Atomic, Molecular and Optical Physics, 29, 331–338. https://doi.org/10.1088/0953-4075/29/2/020
Gérard, J. C., Bougher, S. W., López-Valverde, M. A., Pätzold, M., Drossart, P., & Piccioni, G. (2017). Aeronomy of the Venus upper atmosphere. Space Science Reviews, 212, 1617–1683. https://doi.org/10.1007/s11214-017-0422-0
Gérard, J. C., Gkouvelis, L., Ritter, B., Hubert, B., Jain, S. K., & Schneider, N. M. (2019). MAVEN-IUVS observations of the CO2+ UV doublet and CO Cameron bands in the Martian thermosphere: Aeronomy, seasonal, and latitudinal distribution. Journal of Geophysical Research: Space Physics, 124, 5816–5827. https://doi.org/10.1029/2019JA026596
Gérard, J. C., Hubert, B., Gustin, J., Shematovich, V., Bisikalo, D. V., Gladstone, G. R., & Esposito, L. W. (2011). EUV spectroscopy of the Venus EUV dayglow with UVIS on Cassini. Icarus, 211, 70–80. https://doi.org/10.1016/j.icarus.2010.09.020
Gilijamse, J. J., Hoekstra, S., Meek, S. A., Metsälä, M., van de Meerakker, S. Y. T., & Meijer, G. (2007). The radiative lifetime of metastable CO (a 3Π, v = 0). The Journal of Chemical Physics, 127(22), 221102. https://doi.org/10.1063/1.2813888
González-Galindo, F., Chaufray, J. Y., Forget, F., García-Comas, M., Montmessin, F., Jain, S. K., & Stiepen, A. (2018). UV dayglow variability on Mars: Simulation with a global climate model and comparison with SPICAM/MEx data. Journal of Geophysical Research: Planets, 123(7), 1934–1952. https://doi.org/10.1029/2018JE005556
González-Galindo, F., Jiménez-Monferrera, S., López-Valverde, M. A., García-Comas, M., & Forget, F. (2019). ‘On the derivation of temperature from dayglow emissions on Mars’ upper atmosphere. EPSC-DPS Joint Meeting 2019. Vol. 13. EPSC-DPS2019-888-1. Geneva: EPSC Abstracts, September 2019. Retrieved from https://meetingorganizer.copernicus.org/EPSC-DPS2019/EPSC-DPS2019-888-1.pdf
Herzberg, G., Hugo, T. J., Tilford, S. G., & Simmons, J. D. (1970). Rotational analysis of the forbidden d 3 Δi ← X 1Σ+ absorption bands of carbon monoxide. Canadian Journal of Physics, 48(24), 3004–3015. https://doi.org/10.1139/p70-373
Holsclaw, G. (2020). v1.0 Ajello-Lab/data_reduction: First release of Ajello-Lab data reduction IDL routine. [Data analysis scripts]. https://doi.org/10.5281/zenodo.4270480
Hubert, B., Gérard, J.-C., Gustin, J., Shematovich, V. I., Bisikalo, D. V., Stewart, A. I., & Gladstone, G. R. (2010). UVIS observations of the FUV OI and CO 4P Venus dayglow during the Cassini flyby. Icarus, 207(2), 549–557. https://doi.org/10.1016/j.icarus.2009.12.029
Huschilt, J., Dassen, H., & McConkey, J. (1981). Vacuum ultraviolet excitation of N2 by low energy electrons: Polarization and excitation-function measurements. Canadian Journal of Physics, 59(12), 1893–1901. https://doi.org/10.1139/p81-250
Itikawa, Y. (2002). Cross sections for electron collisions with carbon dioxide. Journal of Physical and Chemical Reference Data, 31(3), 749–767. https://doi.org/10.1063/1.1481879
Itikawa, Y. (2015). Cross sections for electron collisions with carbon monoxide. Journal of Physical and Chemical Reference Data, 44(1), 03105. https://doi.org/10.1063/1.4913926
Jain, S. K., Stewart, A. I. F., Schneider, N. M., Deighan, J., Evans, J. S., Stevens, M. H., et al. (2015). The structure and variability of Mars upper atmosphere as seen in MAVEN/IUVS dayglow observations. Geophysical Research Letters, 42(21), 9023–9030. https://doi.org/10.1002/2015GL065419
Jakosky, B. M., Lin, R. P., Grebowsky, J. M., Luhmann, J. G., Mitchell, D. F., Beutelschies, G., et al. (2015). The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Space Science Reviews, 195(1–4), 3–48. https://doi.org/10.1007/s11214-015-0139-x
Judge, D. L., & Lee, L. C. (1973). Cross sections for the production of CO (a' 3Σ+, d 3Δi, and e 3Σ− → a 3Π) fluorescence through photodissociation of CO2. The Journal of Chemical Physics, 58(1), 104–107. https://doi.org/10.1063/1.1678892
KanikNoren, I. C., Makarov, O. P., Vattipalle, P., Ajello, J. M., & Shemansky, D. E. (2003). Electron impact dissociative excitation of O2: 2. Absolute emission cross sections of OI(130.4 nm) and OI (135.6 nm) lines. Journal of Geophysical Research, 108(E11), 5126. https://doi.org/10.1029/2000JE001423
Krasnopolsky, V. A., & Feldman, P. D. (2002). Far ultraviolet spectrum of Mars. Icarus, 160(1), 86–94. https://doi.org/10.1006/icar.2002.6949
Krupenie, P. H. (1966). The band spectrum of carbon monoxide. National Standard Reference Data Series, Vol. 5. Washington, DC: NBS.
Leblanc, F., Chaufray, J. Y., & Bertaux, J.-L. (2007). Martian dayglow as seen by the SPICAM UV spectrograph on Mars Express. Geophysical Research Letters, 34, L02206. https://doi.org/10.1029/2006GL028437
Leblanc, F., Chaufray, J. Y., Lilensten, L., Witasse, O., & Bertaux, J. L. (2006). Martian dayglow as seen by the SPICAM UV spectrograph on Mars Express. Journal of Geophysical Research, 111, E09S11. https://doi.org/10.1029/2005JE002664
Lee, R., & Ajello, J. (2020). Reduced MAVEN IUVS Breadboard data used for analyses in Lee et al. 2020 Laboratory Study of the Cameron Bands. The first negative bands and fourth positive bands by electron impact on CO [data set] Boulder, CO: University of Colorado. https://doi.org/10.25810/M49V-G348
Lee, L. C., & Judge, D. L. (1973). Population distributions of triplet vibrational levels of CO produced by photodissociation of CO2. Canadian Journal of Physics, 51(4), 378–381. https://doi.org/10.1139/p73-048
Mahaffy, P. R., Benna, M., Elrod, M., Yelle, R. V., Bougher, S. W., Stone, S. W., & Jakosky, B. M. (2015). Structure and composition of the neutral upper atmosphere of Mars from the MAVEN NGIMS investigation. Geophysical Research Letters, 42(21), 8951–8957. https://doi.org/10.1002/2015GL065329
Makarov, O. P., Kanik, I., & Ajello, J. M. (2003). Electron impact dissociative excitation of O2: 1. Kinetic energy distributions of fast oxygen atoms. Journal of Geophysical Research, 108(E11), 5125. https://doi.org/10.1029/2000JE001422
Malone, C. P., Johnson, P. V., McConkey, J. W., Ajello, J. M., & Kanik, I. (2008). Dissociative excitation of N2O by electron impact. Journal of Physics B: Atomic, Molecular and Optical Physics, 41(9), 095201. https://doi.org/10.1088/0953-4075/41/9/095201
McClintock, W. E., Schneider, N. M., Holsclaw, G. M., Clarke, J. T., Hoskins, A. C., Stewart, I., et al. (2015). The imaging ultraviolet spectrograph (IUVS) for the MAVEN mission. Space Science Reviews, 195(1–4), 75–124. https://doi.org/10.1007/s11214-014-0098-7
Meléndez, F. J., Sandoval, L., & Palma, A. (2002). Franck–Condon factors for diatomic molecules with anharmonic corrections. Journal of Molecular Structure: THEOCHEM, 580(1–3), 91–99. https://doi.org/10.1016/S0166-1280(01)00599-1
Morgan, L. A., & Tennyson, J. (1993). Electron impact excitation cross sections for CO. Journal of Physics B: Atomic, Molecular and Optical Physics, 26, 2429–2441. https://doi.org/10.1088/0953-4075/26/15/026
Morton, D. C., & Noreau, L. (1994). A Compilation of Electronic Transitions in the CO Molecule and the Interpretation of Some Puzzling Interstellar Absorption Features. The Astrophysical Journal Supplement Series, 95, 301–343. https://doi.org/10.1086/192100
Noren, C., Kanik, I., Ajello, J. M., McCartney, P., Makarov, O. P., McClintock, W. E., & Drake, V. A. (2001). Emission cross section of OI (135.6 nm) at 100 eV resulting from electron-impact dissociative excitation of O2. Geophysical Research Letters, 28(7), 1379–1382. https://doi.org/10.1029/2000GL012577
Saunders, R. D., Ott, W. R., & Bridges, J. M. (1978). Spectral irradiance standard for the ultraviolet: The deuterium lamp. Applied Optics, 17(4), 593–600. https://doi.org/10.1364/AO.17.000593
Shematovich, V. I., Bisikalo, D. V., Gérard, J.-C., Cox, C., Bougher, S. W., & Leblanc, F. (2008). Monte Carlo model of electron transport for the calculation of Mars dayglow emissions. Journal of Geophysical Research, 113(E2), E02011. https://doi.org/10.1029/2007JE002938
Shematovich, V. I., Bisikalo, D. V., & Ionov, D. E. (2015). Suprathermal particles in XUV-heated and extended exoplanetary upper atmospheres. In H. Lammer & M. Khodachenko (Eds.), Characterizing stellar and exoplanetary environments. Astrophysics and space science library (Vol. 411, pp. 105–136). Cham, Switzerland: Springer. https://doi.org/10.1007/978-3-319-09749-7_6
Simon, C., Witasse, O., Leblanc, F., Gronoff, G., & Bertaux, J.-L. (2009). Dayglow on Mars: Kinetic modeling with SPICAM UV limb data. Planetary and Space Science, 57(8–9), 1008–1021. https://doi.org/10.1016/j.pss.2008.08.012
Slanger, T. G., Cravens, T. E., Crovisier, J., Miller, S., & Strobel, D. F. (2008). Photoemission phenomena in the solar system. Space Science Reviews, 139(1–4), 267–310. https://doi.org/10.1007/s11214-008-9387-3
Steffl, A. J., Young, L. A., Strobel, D. F., Kammer, J. A., Evans, J. S., Stevens, M. H., et al. (2020). Pluto's ultraviolet spectrum, surface reflectance, and airglow emissions. The Astronomical Journal, 159(6), 274. https://doi.org/10.3847/1538-3881/ab8d1c
Stevens, M., Evans, J. S., Schneider, N. M., Stewart, A. I. F., Deighan, J., Jain, S. K., et al. (2015). New observations of molecular nitrogen in the Martian upper atmosphere by IUVS on MAVEN. Geophysical Research Letters, 42(21), 9050–9056. https://doi.org/10.1002/2015GL06531
Strickland, D. J., Bishop, J., Evans, J. S., Majeed, T., Shen, P. M., Cox, R. J., Link, R., & Huffman, R. E. (1999). Atmospheric ultraviolet radiance integrated code (AURIC): Theory, software architecture, inputs, and selected results. Journal of Quantitative Spectroscopy and Radiative Transfer, 62(6), 689–742. https://doi.org/10.1016/S0022-4073(98)00098-3
Strickland, D. J., Book, D. L., Coffey, T. P., & Fedder, J. A. (1976). Transport equation techniques for the depositions of auroral electrons. Journal of Geophysical Research, 81(16), 2755–2764. https://doi.org/10.1029/JA081i016p02755
Strobl, K. H., & Vidal, C. R. (1987). Radiative lifetimes of selected rovibronic triplet levels of the CO molecule. The Journal of Chemical Physics, 86(1), 62–70. https://doi.org/10.1063/1.452592
Szajna, W., Kepa, R., & Zachwieja, M. (2004). Reinvestigation of the B 2Σ+ → X 2Σ+ system in the CO+ molecule. The European Physical Journal D-Atomic, Molecular, Optical and Plasma Physics, 30(1), 49–55. https://doi.org/10.1140/epjd/e2004-00060-0
Tilford, S. G., & Simmons, J. D. (1972). Atlas of the Observed Absorption Spectrum of Carbon Monoxide Between 1060 and 1900 Å. Journal of Physical and Chemical Reference Data, 1(1), 147–188. https://doi.org/10.1063/1.3253097
van Dishoeck, E. F., & Black, J. H. (1986). Comprehensive models of diffuse interstellar clouds: Physical conditions and molecular abundances. Astrophysical Journal Supplement Series, 62, 109–145. https://doi.org/10.1086/191135
Veibell, V. (2020). v1.0 Ajello-Lab/analysis: First release of Ajello-Lab data analysis scripts. [Data analysis scripts]. https://doi.org/10.5281/zenodo.4270483
Yonker, J. D., & Bailey, S. M. (2020). N2(A) in the terrestrial atmosphere. Journal of Geophysical Research: Space Physics, 125, e2019JA026508. https://doi.org/10.1029/2019JA026508
Zetner, P. W., Kanik, I., & Trajmar, S. (1998). Electron impact excitation of the a 3Π, a' 3Σ+, d 3Δi, and A 1Π states of CO at 10.0, 12.5 and 15.0 eV impact energies. Journal of Physics B: Atomic, Molecular and Optical Physics, 31(10), 2395–2413. https://doi.org/10.1088/0953-4075/31/10/025
Zobel, J., Mayer, U., Jung, K., & Ehrhardt, H. (1996). Absolute differential cross sections for electron-impact excitation of CO near threshold: I. The valence states of CO. Journal of Physics B: Atomic, Molecular and Optical Physics, 29(4), 813–838. https://doi.org/10.1088/0953-4075/29/4/021
