Cross Sections and Rate Coefficients for Vibrational Excitation of H2O by Electron Impact

Mehdi Ayouz , A Faure (1) , Jonathan Tennyson , Maria Tudorovskaya , Viatcheslav Kokoouline

1 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

Cross-sections and thermally averaged rate coefficients for vibration (de-)excitation of a water molecule by electron impact are computed; one and two quanta excitations are considered for all three normal modes. The calculations use a theoretical approach that combines the normal mode approximation for vibrational states of water, a vibrational frame transformation employed to evaluate the scattering matrix for vibrational transitions and the UK molecular R-matrix code. The interval of applicability of the rate coefficients is from 10 to 10,000 K. A comprehensive set of calculations is performed to assess uncertainty of the obtained data. The results should help in modelling non-LTE spectra of water in various astrophysical environments.

Mots clés: water; vibrational excitation; R-matrix; electron-molecule collisions; interstellar medium

Domaines: Physique [physics]

Mehdi Ayouz, A Faure, Jonathan Tennyson, Maria Tudorovskaya, Viatcheslav Kokoouline. Cross Sections and Rate Coefficients for Vibrational Excitation of H2O by Electron Impact. Atoms, 2021, 9 (3), pp.62. ⟨10.3390/atoms9030062⟩. ⟨hal-03441826⟩