Bar-Halo Friction in Galaxies III: Particle Number Requirements for Simulations

Understand

The question whether the dark matter halo density in the centers of galaxies could be changed through interactions with a rotating bar in the baryonic disk is of considerable current interest.

• While N-body simulations have been used to address this question, it has also been claimed that results from such simulations cannot be trusted.
• Based on a perturbative treatment of resonant exchanges between orbits and a rotating perturbation, Weinberg & Katz contend that N-body simulations of this process will not reveal the continuum result unless many more than the usual numbers of particles are employed.
• Here I report a study designed to examine their contention, finding results that show no dependence on the number of particles over the range usually employed up to that advocated by these authors.