Abstract
We present a simple model of CO excitation in comets, including solar pumping, ro-vibrational (de)excitation by H\(_2\)O and electron collisions, and fluorescence. Collisional data for H\(_2\)O−CO are taken from quantum statistical calculations while Born dipole cross-sections are calculated for electron-CO collisions. In the non-LTE regime, i.e. at H\(_2\)O densities in the range \(10^{3}\)–\(10^{8}\) cm\(^{-3}\), CO excitation is found to be largely dominated by H\(_2\)O collisions, with electron collisions becoming significant only for density profiles with scaling factors \(x_{n_e}> 3\).
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Nicolas Biver is acknowledged for useful discussions about the electron density and temperature profiles.
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Faure, A., Lique, F., Loreau, J. (2023). The Effect of H\(_2\)O and Electron Collisions on Rotational Populations of Cometary CO. In: Mennella, V., Joblin, C. (eds) European Conference on Laboratory Astrophysics ECLA2020. ECLA 2021. Astrophysics and Space Science Proceedings, vol 59. Springer, Cham. https://doi.org/10.1007/978-3-031-29003-9_32
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