The Ultimate Fate of Cosmic Rays from Galaxies and their Role in the Intergalactic Medium

Understand

The majority of cosmic rays (CRs) generated by star-forming galaxies escape them and enter the intergalactic medium (IGM).

• Galactic wind termination shocks might also accelerate CRs.
• I show that the mean pressure of these CRs can reach to within an order of magnitude of the mean Lyman-alpha forest thermal pressure.
• At z >~ 1, their pressure may have even been dominant.