Speaker
Description
Simulated galaxies and their dark matter (DM) halos are resolved by fewer particles than there are stars and DM particles in real galaxies and, as a result, are subject to spurious evolution due to gravitational scattering. I will present results from a suite of idealized simulations designed to study the effect of spurious collisional heating on the kinematics and morphologies of simulated galactic discs. I will then present results from two simulations from the EAGLE Project that differ only in the mass resolution of their DM component (one having and equal number of DM and baryonic particles, the other having a factor of seven more DM particles) but keep all other numerical and subgrid parameters fixed. These simulations indicate that a number of global properties of simulated galaxies and halos are unaffected by spurious collisional heating but, below a characteristic mass scale, their structural and kinematic properties are affected. A simple semi-empirical model rooted in analytic theory can be used to identify the characteristic halo mass above which the structural and kinematic properties of galaxies are robust to spurious collisional heating.
