2024/12/16 by Roark Habegger, Habegger, Roark, Ellen G. Zweibel +1
Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #Atomic and Subatomic Physics Research #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.2412.12249
openalex publication_date 2024/12/16 · openalex created_date 2024/12/19 · openalex updated_date 2026/07/28
Supernova energy drives interstellar medium (ISM) turbulence and can help launch galactic winds. What difference does it make if 10% of the energy is initially deposited into cosmic rays? To answer this question and study cosmic-ray feedback, we perform galactic patch simulations of a stratified ISM. We compare two magnetohydrodynamic and cosmic ray (MHD+CR) simulations, which are identical except for how each supernova's energy is injected. In one, 10% of the energy is injected as cosmic-ray energy. In the other case, energy injection is strictly thermal and kinetic. We find that cosmic-ray injections drive a faster, hotter, and more massive outflow long after the injections occur. Both simulations show the formation of cold clouds (with a total mass fraction >50%) through the Parker instability and thermal instability. The Parker instability simultaneously produces high mass loading factors η> 103 as it requires few supernovae. We also show how the Parker instability naturally leads to a decorrelation of cosmic-ray pressure and gas density. This decorrelation leads to a significant decrease in the calorimetric fraction for injected cosmic rays, but it depends on having a highly resolved magnetic field.