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Ven. 14/04/2023 15:00 Salle des Séminaires, Bâtiment 21, Etage 4 Séminaire
PIRLOT Paul (Institut de Physique de Rennes)
Collisional excitation of radical molecules in the interstellar medium
Sommaire:
The modeling and interpretation of molecular spectra from interstellar environments require the knowledge of both radiative and collisional processes of energy transfer between chemical species. Accurate state-to-state rate coefficients of interstellar molecules in collision with the main collisional partners H2, H and He are then necessary.
Such collisional data can be obtained through quantum time-independant scattering calculations by resolving the close-coupled equations. This method is nowadays one of the most accurate for describing collisions at very low temperature. However, species such as radicals possess very complex energetic structures because of the presence of non zero electronic and even nuclear spins. Also, accurate description of fine and hyperfine transitions implying two interacting molecules is a true theoretical challenge. Then, this method is not fully applicable in terms of memory and CPU time.
This thesis work consists in quantifying the collisional excitation of these open-shell molecules in astrophysical media. The development of methodological and numerical tools are then required to overcome these problems and to characterize physical and chemical processes as precisely as possible. The provided collisional data are expected to interpret observations and corroborate experiments performed in laboratory. Pour plus d'informations, merci de contacter Scribano Y.
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