18 juin 2021 @ 11 h 00 min – 12 h 00 min
Title: Non-thermal cosmic ray desorption of ices mantles and complex organic molecules
Speaker: Emmanuel Dartois (Institut des Sciences Moléculaires d’Orsay (ISMO))
In the dense and cold zones of the interstellar medium, dust grains are covered with volatile solids, the interstellar ice mantles, which are relatively protected from ambient radiation fields external to dense clouds. However, cosmic radiation consisting of high-energy particles can penetrate deeply into these clouds and induces complex chemistry through its direct interaction (radiolysis), or indirect photolysis of dust grains (production of a secondary vacuum ultraviolet VUV radiation field by interaction with the gas, mainly molecular hydrogen).
The chemical evolution observed in high-density regions, from dense clouds to protoplanetary disks, and the release of species condensed on dust grains, is one key parameter to be taken into account in interpretations of both observations and models. Cosmic-ray-induced sputtering is one of the important desorption mechanisms at work in such astrophysical environments.
In this talk I will briefly describe the evolution, and the results based on laboratory experiments of interstellar ices analogues exposed to CRs simulated on particles accelerators, in the electronic regime of interaction, with a focus on the sputtering of ice mantles in an astrophysical context.