- Matthew Lehnert (GEPI, Observatoire de Paris)
Galactic stellar disks account for only a small portion of the total baryonic mass of the local volume, but they dominate the angular momentum budget of the Universe. The formation and evolution of galactic disks are intertwined with the development of angular momentum with cosmic time. Although a detailed picture of the angular momentum evolution of the baryons in a hierarchical universe is still lacking, it is clear that merging of galaxies is one of the fundamental drivers of galaxy evolution with perhaps an especially important role for mergers with large mass ratios — minor mergers. In order to gain more insight in the physical processes that determine the evolution of angular momentum in galaxies we explore, through the use of N- body/Smooth Particle Hydrodynamical numerical simulations, the angular momentum redistribution during a large number of minor galaxy mergers and investigate their impact on the dynamical and morphological properties of disks. Overall, this thesis study demonstrates the fundamental role angular momentum plays during galaxy minor merger processes in altering stellar disk properties and driving galaxy evolution, and indicates that minor mergers may be a viable mechanism to explain many of the observed properties of disk galaxies in the local Universe.