Le 20 novembre 2014
De 12h30 à 13h30
Benjamin MOSTER
Cambridge University
The field of galaxy formation is on the cusp of a tide of new data. To understand these in the context of an evolutionary picture, we need models that interpret the observed trends. Hydrodynamical simulations, have become the main tool for this. However, as the resolution in simulations is finite, not all of the physical processes are resolved. Consequently, simple prescriptions (`sub-grid’ models) must be resorted to. Empirical galaxy formation models, on the other hand, provide a unique and direct link between galaxies and dark matter haloes, and do not depend on model assumptions on unresolved physics, only on gravity and observed galaxy properties. They are based on a parameterised relation between the stellar mass of a galaxy and the mass of the halo in which it is embedded. I will give a short overview of current empirical models and present a path to the next generation of empirical models. The evolution of individual galaxies is modelled by following the growth histories of their haloes as extracted from numerical simulations, and use empirical relations to derive galaxy properties such as star formation rate and gas mass. This new technique can then be applied to make predictions for galaxies at high redshift and their evolution through cosmic time, e.g. galaxy merger rates, which will be testable in future surveys.