How can oscillating gas potentials transfer energy to dark matter and form a core?

Recurrent gas expansion and contraction provide a mechanism for changing a dark halo’s central structure.

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

The Core-Cusp Problem in Cold Dark Matter Halos and Supernova Feedback: Effects of Oscillation. Ogiya, Go; Mori, Masao, Astrophysical Journal, 793, 46 (2014).

arXiv:1206.5412 Publication · DOI

Approach

An analytical resonance treatment is checked with N-body simulations of halo responses to a periodically varying baryonic potential.

Main result

Energy transfer is effective when the potential oscillation period is close to the local halo dynamical time. The model relates this condition to the resulting core radius.

Scientific implications

The timing of feedback cycles matters alongside their energy: a changing gravitational field can heat collisionless dark matter.

Scope and limitations

The imposed oscillating potential idealizes the gas cycle. The study tests the dynamical response rather than a full self-consistent star-formation history.