January 23
Michael Kuhlen (UC
Berkeley)
Computational Cosmology and Galaxy Formation
Fueled by
continuing advances in numerical methods and computational capabilities, the
future of galaxy formation theory is going to be driven by numerical
simulations. Yet computational galaxy formation is extremely challenging, owing
to the multitude of important physical processes and the wide range of scales
over which they operate. Much of the galaxy formation simulation work to date
has relied on simple, and often ad-hoc, subgrid
models for star formation and feedback. In this talk I will describe my recent
efforts to improve this situation by including more realistic and
physics-driven treatments of some of the relevant processes. As one example, I
will discuss cosmological adaptive mesh refinement simulations in which star
formation is regulated by the local abundance of molecular hydrogen. These simulations
reproduce much of the observational phenomenology of star formation rates as a
function of atomic and molecular gas content and metallicity.
At the same time this new piece of physics leads to a suppression of the
stellar content of low mass dark matter halos, thereby helping to explain the
vexing dwarf galaxy problem.