A two-component model for the high-energy variability of blazars. Application to PKS 2155-304

TL;DR

This paper presents a two-component model for blazar high-energy variability, combining a steady jet emission with a dynamic inner beam, successfully applied to PKS 2155-304 to explain observed emissions and neutrino fluxes.

Contribution

The paper introduces a novel two-component model incorporating both steady jet and inner beam contributions, including particle transport and local pair injections, to explain blazar variability.

Findings

Reproduces PKS 2155-304's quiescent emission state

Predicts neutrino flux detectable by KM3NeT

Explains short-term variability via local pair injections

Abstract

We study the production of VHE emission in blazars as a superposition of a steady component from a baryonic jet and a time- dependent contribution from an inner e-e+ beam launched by the black hole. Both primary relativistic electrons and protons are injected in the jet, and the particle distributions along it are found by solving a one-dimensional transport equation that accounts for convection and cooling. The short-timescale variability of the emission is explained by local pair injections in turbulent regions of the inner beam. For illustration, we apply the model to the case of PKS 2155-304, reproducing a quiescent state of emission with inverse Compton and synchrotron radiation from primary electrons, as well as proton-proton interactions in the jet. The latter also yield an accompanying neutrino flux that could be observed with a new generation km-scale detector in the northern hemisphere such as KM3NeT.