Intergalactic electromagnetic cascade component of observable blazar emission

TL;DR

This paper reviews intergalactic electromagnetic cascades affecting blazar spectra, introduces a new approximation for gamma-ray mean free path, and analyzes angular patterns of cascade emission with an example fit to observational data.

Contribution

It proposes a novel approximation for gamma-ray mean free path and examines angular distributions of cascade emissions in blazar observations.

Findings

New approximation for gamma-ray mean free path

Analysis of angular broadening patterns

Successful fit to blazar spectrum data

Abstract

Secondary {\gamma}-rays from intergalactic cascades may contribute to observable spectra of blazars, also modifying observable angular and temporal distributions. In this paper we briefly review basic features of intergalactic electromagnetic cascade physics, suggest a new approximation for {\gamma}-ray mean free path, consider angular patterns of magnetically broadened cascade emission, and present an example of a fit to the observable blazar spectrum.