Photophysique VUV de Molécules Prébiotiques dans le contexte des exoplanètes
LEACH, Sydney
Laboratoire d’Etude du Rayonnement et de la Matière en Astrophysique - Observatoire de Paris-Meudon, 92195-Meudon, France
Sydney.Leach@obspm.fr

One of the important aims of the study of extrasolar planets is to identify markers that could be associated with the presence or possible future existence of life on these far-off objects. Thus the identification of prebiotic molecules and elementary biotic building blocks is a valid objective. Since the atmospheres of extrasolar planets is increasingly studied by spectroscopic means, permitting the prevailing physical environment, in particular the local radiation field, to be determined, it is imperative to understand the viability of prebiotic and biotic molecules under these conditions. Furthermore, these extrasolar planets will most probably also be subject to inflow of material from local comets and asteroids and these could give rise to observable effects. I will present the results of extensive studies of the VUV spectroscopy and photophysics of a number of prebiotic molecules, such as ammonia, formic acid, acetic acid, acetonitrile, formamide and acetamide, as well as recognised biological building blocks such as the amino acids glycine, alanine, valine etc, and a number of purines and pyrimidines, including the nucleic acid bases adenine, thymine and uracil. These results will be set in the context of the survivability of these species under various conditions of irradiation and in settings corresponding to (exo)-planetary atmospheres and cometary and asteroidal environments.

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