Dark matter distribution at the centres of dwarf galaxies

I present the comparison between high-resolution dark matter density profiles of 7 dwarf
galaxies culled from “The HI Nearby Galaxy Survey” (THINGS) and those of cosmological
hydrodynamic simulations recently performed by Governato et al. (2010). The simulations
properly include not only dark matter but  also baryons, such as stars and gas in dwarf
galaxy-size dark matter halos whose dynamical masses and virial rotation velocities are comparable
to those of the THINGS dwarf galaxies. More importantly, they properly take baryonic feedback
processes such as gas cooling, star formation, cosmic uv field heating, SNe-driven outflows etc.
into account. From the simulations, in a same way as observers usually do, we construct
data cubes, extract velocity fields, derive rotation curves and lastly derive dark mat-
ter density profiles by performing mass modeling. We then compare the derived dark
matter distributions of the simulations with those of 7 THINGS dwarf galaxies. The derived
dark matter distributions of both observations and simulations are well consistent with
each other in terms of (1) the rotation curve shape and (2) the logarithmic inner density
slope α of the mass density profiles. This implies that the baryonic feedback processes in dwarf
galaxies can be a solution for the small-scale problems in Lambda Cold Dark Matter simulations.