Cosmological Simulations of Dwarf Galaxies with Cosmic Ray Feedback
  We perform zoom-in cosmological simulations of a suite of dwarf galaxies,
examining the impact of cosmic-rays generated by supernovae, including the
effect of diffusion. We first look at the effect of varying the uncertain
cosmic ray parameters by repeatedly simulating a single galaxy. Then we fix the
comic ray model and simulate five dwarf systems with virial masses range from
8-30 $\times 10^{10}$ Msun. We find that including cosmic ray feedback (with
diffusion) consistently leads to disk dominated systems with relatively flat
rotation curves and constant star formation rates. In contrast, our purely
thermal feedback case results in a hot stellar system and bursty star
formation. The CR simulations very well match the observed baryonic
Tully-Fisher relation, but have a lower gas fraction than in real systems. We
also find that the dark matter cores of the CR feedback galaxies are cuspy,
while the purely thermal feedback case results in a substantial core.
