Unraveling the surface formation of regular and deuterated water in space : a combined laboratory and computational study

This thesis is devoted to the study of regular and deuterated water in ices and on surfaces against an interstellar background. A large network for the formation of regular water has been studied with the use of a Kinetic Monte Carlo model. A specific reaction has been investigated as well: H2 + O -> OH + H. Furthermore, in the light of deuterium fractionation, a thermal study on deuteron scrambling in the ice has been performed: H2O + D2O -> 2 HDO. Finally, two low-temperature routes relevant to HDO formation have been investigated: H2O + OD -> OH + HDO and D2O + OH -> OD + HDO.Laboratory astrophysics and astrochemistr