Molecular mobility on interstellar ices. Computational nanoscience on the galactic scale

Abstract

Understanding nature on the largest scales can sometimes require minute details of its very smallest processes. This is certainly true in the field of astrochemistry, the study of the formation and evolution of molecules in outer space; in particular in molecular clouds. Here, in the birthplace of stars and planets, a diverse and exotic molecular inventory is observed. Knowledge of the chemistry in these environments is not only a fundamental scientific objective, but also helps us understand the origin of matter on Earth. In this thesis, the adaptive kinetic Monte Carlo method is used to model the dynamics of crucial astrochemical processes at the level of individual atoms in the extreme conditions of the interstellar medium. Results are obtained on the surface mobility and adsorption properties of key molecules such as water, carbon monoxide, and carbon dioxide. Experiments are performed to verify the predictions of the simulations and essential process properties are presented in a pragmatic and practical form, for use by the astrochemical modeling community.