Université Paul Sabatier - Bat. 3R1b4 - 118 route de Narbonne 31062 Toulouse Cedex 09, France

Accueil > Événements > Séminaire 2018

Experimental Astrochemistry : Study of reactions at low temperature and application to interstellar clouds and planetary atmospheres

Séminaire LCAR/IRAP - mercredi 19 décembre 14h
Salle de séminaire IRSAMC - Bât 3R1b4

Dianailys Nunez-Reyes
Institut des Sciences Moléculaires - Bordeaux

Abstract : The last 50 years has been characterized by the fast development of astrochemistry as a science, where a combination of astronomical observations, chemical modelling and laboratory experiments are used to explain the nature and abundance of the molecules in the interstellar medium and in planetary atmospheres. To date, more than 200 species have been detected in the interstellar medium and only a few reactions that might take place among these species have been studied over a wide temperature range (from astrochemistry to combustion temperatures). However, the rate constants for many potentially important processes remain unknown at low temperature, which represents a source of error in astrochemical models. In this presentation, I will report kinetic studies of reactive and non-reactive removal processes between excited state atoms [C(1D), O(1D) and N(2D)] with several molecules in order to quantify their importance in the chemistry of planetary atmospheres. Furthermore, I will also discuss the reaction between carbon atoms in their ground electronic state (3P) with water and its relevance to the chemistry of the interstellar clouds. Here, the rate constants and branching ratios were determined over the 50 - 296 K temperature range using a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme) apparatus coupled with pulsed laser photolysis (PLP) and vacuum ultraviolet laser-induced fluorescence (VUV-LIF).