Cosmic ray feedback in the FIRE simulations: constraining cosmic ray propagation with GeV gamma ray emission

Understand

We present the implementation and the first results of cosmic ray (CR) feedback in the Feedback In Realistic Environments (FIRE) simulations.

• We investigate CR feedback in non-cosmological simulations of dwarf, sub-$L\star$ starburst, and $L\star$ galaxies with different propagation models, including advection, isotropic and anisotropic diffusion, and streaming along field lines with different transport coefficients.
• We simulate CR diffusion and streaming simultaneously in galaxies with high resolution, using a two moment method.
• We forward-model and compare to observations of $\gamma$-ray emission from nearby and starburst galaxies.