Swift heavy ion modifications of astrophysical water ice
Résumé
In the relatively shielded environments provided by interstellar dense clouds in our Galaxy, infrared
astronomical observations have early revealed the presence of low temperature (10–100 K) ice mantles
covering tiny grain ‘‘cores” composed of more refractory material. These ices are of specific interest
because they constitute an interface between a solid phase under complex evolution triggered by energetic
processes and surface reactions, with a rich chemistry taking place in the gas phase. The interstellar
ice mantles present in these environments are immersed, in addition to other existing radiations fields, in
a flux of cosmic ray particles that can produce new species via radiolysis processes, but first affects their
structure, which may change and also induces desorption of molecules and radicals from these grains.
Theses cosmic rays are simulated by swift ions in the laboratory for a better understanding of astrophysical
processes.