Analytical and numerical models of radiative transfer in galaxies

Résumé

Galaxy formation and evolution involve several physical processes where stars, gas and dust play important roles. While analytical and numerical models have successfully accounted for most of them over the years, radiative transfer, that considers the interaction between light and the interstellar medium, is still the elephant in the room. Despite its importance as a driver of galactic evolution and as one of the main observables, radiation is often treated under very restrictive assumptions because an on-the-fly radiative transfer prescription is computationally expensive. This thesis advocates the importance and feasibility of including radiation by developing several models and codes with modest computational requirements. To illustrate this, I include radiation fields into the well-studied problem of supernova remnant evolution to study its effects, highlighting the main differences and improvements with respect to previous works in the literature. Then, I model the interstellar radiation field of the Milky Way in a self-consistent way, based on a distribution of stars, gas and dust predicted by chemical evolution models. This opens the door to use the interstellar radiation field both as a prediction to calibrate evolutionary galaxy models, as well as an efficient method to consider this ingredient on other physical processes, as done with supernova remnants.