The Core-Cusp Problem in Cold Dark Matter Halos and Supernova Feedback: Effects of Oscillation

TL;DR

This paper explores how recurrent starburst-driven gas oscillations in galaxies can induce a resonance with dark matter particles, leading to the transformation of cuspy dark matter profiles into cores, supported by analytical and simulation results.

Contribution

It introduces a resonance-based mechanism for the cusp-core transition in dark matter halos driven by supernova feedback cycles.

Findings

Resonance between gas oscillation period and local dynamical time triggers core formation.

Analytical model predicts core radius consistent with N-body simulation results.

Energy transfer via resonance explains the cusp-core transformation in CDM halos.

Abstract

This study investigates the dynamical response of dark matter (DM) halos to recurrent starbursts in forming less-massive galaxies to solve the core-cusp problem. The gas, which is heated by supernova feedback after a starburst, expands and the star formation then terminates. This expanding gas loses energy by radiative cooling and then falls back toward the galactic center. Subsequently, the starburst is enhanced again. This cycle of expansion and contraction of the interstellar gas leads to a repetitive change in the gravitational potential of the gas. The resonance between DM particles and the density wave excited by the oscillating potential plays a key role in understanding the physical mechanism of the cusp-core transition of DM halos. DM halos effectively gain kinetic energy from the baryon potential through the energy transfer driven by the resonance between the particles and density waves. We determine that the critical condition for the cusp-core transition is such that the oscillation period of the gas potential is approximately the same as the local dynamical time of DM halos. We present the resultant core radius of a DM halo after the cusp-core transition induced by the resonance by using the conventional mass density profile predicted by the cold dark matter models. Moreover, we verify the analytical model by using $N$-body simulations, and the results validate the resonance model.