Informal Astro Talk
Probing extragalactic magnetic fields, and sites of hadronic acceleration with blazar gamma-ray emission
Gamma-rays with energy exceeding 100 GeV, emitted by blazars, initiate cascades in the intergalactic medium. The angular and temporal distribution of the cascade photons that arrive at the Earth depend on the strength and configuration of extragalactic magnetic fields (EGMFs) in the line of sight. I will discuss how the characteristics (energy dependence, angular size, and shape) of the observed cascade emission can constrain the EGMF strength and correlation length. In addition, I will show the expected signatures of ultra-high energy cosmic ray acceleration in the gamma-ray spectra of blazars in a range of models, and discuss the detectability of such signatures with upcoming GeV, and TeV gamma-ray observations.