Searching for signatures of electromagnetic cascades in the intergalactic medium initiated by blazars

Abstract

Very high energy (VHE) y-ray astronomy has opened a new window into the Universe at the highest energies, allowing the exploration of unique astrophysical phenomena. This thesis constitutes an observational contribution to understanding the processes in the intergalactic medium as well as the resulting physical structures, in particular pair halos and beam broadened cascade emission. Pair Halos are giant electron-positron structures which are formed due to the development of pair cascades, initiated by interactions of primary multi-TeV photons from high energy extragalactic sources with the extragalactic background photon fields.