Star formation and feedback in simulations of interacting galaxies

Galaxy interactions are a common occurrence during the hierarchical growth of structure and may be a significant driver of galaxy formation and evolution. Motivated by the quest to better understand the star formation induced by galaxy interactions and the properties of merger remnants this dissertation simulates a large series of mergers between observationally motivated disk galaxies including the cooling of gas, star formation and stellar feedback.; Star formation and its associated feedback are captured by simple parameterizations and parameters are selected to match the observed stability and star formation in local spiral galaxies. Using one star formation and feedback model and one set of parameters a large series of galaxy mergers are performed between equivalent galaxies (major mergers) and galaxies of unequal mass (minor mergers). Star formation is generally enhanced during merger events unless the mass ratio is larger than 1:5. The strongest response is found during major mergers, in line with expectations. Of critical importance to the star formation response during galaxy interactions is the internal structure of the progenitor disk galaxies. As with previous studies the presence of a bulge stabilizes galactic disks and suppresses early gas inflow. Also significant is the assumed gas fraction and distribution. Larger gas fractions naturally lead to more star formation and extended gas disks increase the merger induced star burst relative to the quiescent star formation. Smaller progenitor halos have fundamentally different star formation properties than larger progenitor halos, showing larger and more prolonged enhancements of star formation due to the merger event.