Hadronic Interactions of Energetic Charged Particles in Protogalactic
  Outflow Environments and Implications for the Early Evolution of Galaxies
  We investigate the interactions of energetic hadronic particles with the
media in outflows from star-forming protogalaxies. These particles undergo
pion-producing interactions which can drive a heating effect in the outflow,
while those advected by the outflow also transport energy beyond the galaxy,
heating the circumgalactic medium. We investigate how this process evolves over
the length of the outflow and calculate the corresponding heating rates in
advection-dominated and diffusion-dominated cosmic ray transport regimes. In a
purely diffusive transport scenario, we find the peak heating rate reaches
$10^{-26}\;\! {\rm erg~cm}^{-3}\;\! {\rm s}^{-1}$ at the base of the outflow
where the wind is driven by core-collapse supernovae at an event rate of 0.1
$\text{yr}^{-1}$, but does not extend beyond 2 kpc. In the advection limit, the
peak heating rate is reduced to $10^{-28}\;\! {\rm erg~cm}^{-3}\;\! {\rm
s}^{-1}$, but its extent can reach to tens of kpc. Around 10% of the cosmic
rays injected into the system can escape by advection with the outflow wind,
while the remaining cosmic rays deliver an important interstellar heating
effect. We apply our cosmic ray heating model to the recent observation of the
high-redshift galaxy MACS1149-JD1 and show that it could account for the
quenching of a previous starburst inferred from spectroscopic observations.
Re-ignition of later star-formation may be caused by the presence of
filamentary circumgalactic inflows which are reinstated after cosmic ray
heating has subsided.
