Understand
We carry out adaptive mesh refinement (AMR) cosmological simulations of Milky-Way mass halos in order to investigate the formation of disk-like galaxies in a {\Lambda}-dominated Cold Dark Matter model.
- We evolve a suite of five halos to z = 0 and find gaseous-disk formation in all; however, in agreement with previous SPH simulations (that did not include a subgrid feedback model), the rotation curves of all halos are centrally peaked due to a massive spheroidal component.
- Our standard model includes radiative cooling and star formation, but no feedback.
- We further investigate this angular momentum problem by systematically modifying various simulation parameters including: (i) spatial resolution, ranging from 1700 to 212 pc; (ii) an additional pressure component to ensure that the Jeans length is always resolved; (iii) low star formation efficiency, going down to 0.1%; (iv) fixed physical resolution as opposed to comoving resolution; (v) a supernova feedback model which injects thermal energy to the local cell; and (vi) a subgrid feedback model which suppresses cooling in the immediate vicinity of a star formation event.