The core-cusp problem in CDM halos andsupernova feedback

摘要

"The Core-Cusp problem" is one of the open questions on Cold Dark Matter (CDM) cosmology. It is a discrepancy about the mass-density distribution of a dark matter halo between theory and observation. We study about the dynamical response of a virialized system with a central cusp to a mass loss driven by supernova feedback from the galaxy center using collisionless N-body simulations. Our results show that the system expands and recovers a new equilibrium state as a loosely bound core, if a certain fraction of the initial mass is lost from the galactic center on a shorter timescale in comparison to the mean crossing time in the system. The dynamical evolution of the central density profile is determined not only by the amount of gas removal but also by its timescale. We furthermore discuss the relation among the feedback parameters, the star formation rate and the metal enrichment.