The Intrinsic Gamma-Ray Spectrum of TXS 0506+056: Intergalactic Propagation Effects

TL;DR

This paper investigates how intergalactic magnetic fields and background light affect the observed gamma-ray spectrum of blazar TXS 0506+056, providing insights into the intrinsic emission properties of the source.

Contribution

It offers a comprehensive analysis of intergalactic propagation effects, including magnetic fields, on gamma-ray spectra, which are often overlooked in spectral modeling.

Findings

Intergalactic magnetic fields significantly influence gamma-ray propagation.

Attenuation by extragalactic background light alters the observed spectrum.

Intrinsic gamma-ray spectrum can be reconstructed considering these effects.

Abstract

The recent observation of high-energy neutrinos from the 2017 flare of the blazar TXS~0506+056, together with counterparts across the whole electromagnetic spectrum, opens up new possibilities for investigating the properties of this class of objects as well as the traversed medium. Propagation effects such as the attenuation of the very-high-energy gamma-ray component by the extragalactic background light are well known, and usually taken into account when fitting spectral energy distributions of objects. Other effects such as those of intergalactic magnetic fields are, however, often neglected. In this work, we present a comprehensive study of the influence of these fields and the extragalactic background light on the determination of the intrinsic gamma-ray spectrum of this blazar.