Dissertation

Resolving the building blocks of galaxies in space and time

Author: Clauwens, B.J.F.
Date: 06 December 2017
Links: Thesis in Leiden Repository

We investigate the buildup of galaxies from various vantage points. The first two chapters focus on the stellar content of galaxies, especially the distribution of stellar masses at birth and potential variations therein in various galactic environments. We find that in some cases these inferred variations can be due to an underestimation of model and measurement errors. Furthermore, we infer the consequences of these proposed variations on the interpretation of galaxy properties and galaxy formation processes. Chapters 3 and 4 focus on the buildup of galaxies in time through mergers and in-situ star formation. We test and improve observational models that aim to trace galaxies though cosmic time, by applying them to cosmological hydrodynamical simulations, for which we have access to the full history and evolution of galaxies since the beginning of time. The fifth chapter focusses on the buildup of galaxy morphology. We follow the buildup of morphological components in a cosmological simulation, which leads us to conclude that galaxy formation is a three-phase process, consisting of an early, rather disorganised, phase, followed by a phase in which stars are formed primarily in an organised rotating disk, and ending in a late phase of merger-driven spheroid formation.