Speaker
Description
Astrophysical ices, mainly composed of simple molecules such as H2O, CO, CO2, NH3, CH3OH and others are ubiquitous in space: they are present in comets, satellites of planets (e.g Jovian moons) and on the grains of the dense molecular clouds in the interstellar medium. They are constantly exposed to complex and diverse radiation fields and interact with photons, electrons and ions (solar/stellar winds, magnetospheres or/and cosmic rays). This induces several physico-chemical processes such as radiolysis and subsequent formation of new molecules, release of molecules to the gas phase (sputtering, desorption) and structural ice modifications.
During the talk, I will present an overview of results obtained for ion irradiation of ices containing small molecules as well as films of complex organic molecules (e.g. PAHs, nucleobases) performed with the "space simulator" device IGLIAS at CIMAP using GANIL (Caen, France) ion beams. Additional experiments were performed at ATOMKI (Debrecen, Hungary) and GSI (Darmstadt, Germany). Infrared absorption spectroscopy is used to in situ observation of physico-chemical modifications of the icy layers during energetic processing. Ex-situ analysis of residues is performed by e.g. high resolution mass spectrometric methods. Astrophysical application of obtained results will be discussed. Moroeover, the MIRRPLA platform will be also presented. MIRRPLA is a unique multibeam irradiation platform (UV photons, keV electrons and keV-GeV ions), which is under construction at CIMAP laboratory, to investigate the origin and evolution of organic matter of the Solar System. This project is financed by ANR PEPR ("Programmes et équipements prioritaires de recherche") "Origins ».
