Speaker:
Sándor Demes
Univ Rennes, IPR (Institut de Physique de Rennes) - UMR 6251, 35000 Rennes, France
Abstract:
The recent advances in observational tools supported by robust astrochemical models and laboratory techniques allow an accurate determination of the composition and structure of matter in the universe. For example, the number of new species observed in interstellar molecular clouds has been steeply increased recently, confirming the presence of more than 300 types of molecules in such environments to date. Besides simple species, there is a growing trend towards the detection of complex organic molecules, including polycyclic aromatic hydrocarbons. Such increasing chemical complexity is observed not exclusively in interstellar environments, but also in planetary and cometary atmospheres, where in-situ measurements are also available. Apart from the gas-phase studies, the fascinating chemistry of icy grains is also actively studied in different astronomical objects. State-of-the-art scientific methods allow entirely new insights into the rich chemical composition and the mechanism of build-up processes which lead to the formation of complex prebiotic molecules in space. However, to have a detailed understanding of these processes, we need to understand the particular phenomena at the molecular level. This requires a state-to-state investigation of molecular interactions in reactions and collisions with both light and heavier particles abundant in astronomical environments, such as electrons, free atoms, ions, radicals and other neutral molecules, etc.
In my talk, I will shortly summarise our research dedicated to investigate these problems, focusing both on their theoretical and experimental aspects as well as their relation to astronomy and atmospheric science. It will start with the fundamental interaction of electrons with molecules, [1]. This will be followed by a discussion about the interaction of high-energy (keV/MeV) ions with molecular species, providing details about the ionisation, dissociation and electron capture processes [2]. In the last part, the importance of accurate state-to-state description will be illustrated for sub-eV molecular collisions, along with examples of their relevance for astronomy [3]. A brief introduction into the difficulties of low-temperature reaction kinetics studies will be also made with a link to planetary atmosphere studies [4]. Finally, I will give my perspectives and propose possible solutions to some of the most important challenges in these research fields.
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Open to all IP2I members, as well as UCBL and CNRS students and collaborators.
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