Gamma-ray Signatures of Ultra High Energy Cosmic Ray Line-of-sight Interactions

Abstract

Ultra High Energy Cosmic Rays (UHECRs) interact en route to Earth, producing secondary gamma-rays. For the case of high cosmic ray power and weak intergalactic magnetic fields, the deflections of these UHECRs may be small leading to detectable gamma-ray fluxes that point back to their origin. We summarize current results and prospects of detecting a signature of these interactions using the current and next generation of imaging atmospheric Cherenkov telescopes.