Using Mock Velocity Field Observations to Determine the Dark MatterDistribution in Dwarf Galaxies

Abstract

High-resolution Hα velocity fields provide important observational constraints on the dark matter distribution in dwarf and low surface brightness galaxies. These two-dimensional data show that dark matter-dominated galaxies tend to be more consistent with cored halos than cuspy halos, at odds with theoretical expectations. Using N-body/SPH simulations of disk galaxy formation in cuspy spherical and triaxial dark matter halos, as well as cored dark matter halos, we “observe” the simulated galaxies under a variety of realistic observing conditions. We use these mock IFU velocity field observations to determine how well the underlying dark matter halo can be recovered and to test the hypothesis that cusps can be obscured by triaxial dark matter halos.