Shaping the central structure in CDM halos

Abstract

Coupling the dark matter (DM) and baryonic components in galaxies via dynamical friction (by allowing the latter to be clumpy) leads to energy input into the DM. The resulting expanding tendency in the DM component overcomes the competing effect of adiabatic contraction, resulting from the shrinking gas component, and leads to a nearly constant density core. The baryonic mass inflow also leads to the coupling of the structure at the kpc scale and below and that of the structure of the DM at the 10 kpc scale and above, with rate of mass inflow being dependent on the initial halo central concentration. The latter also determines the final halo core radius.