Modelling the emission from blazar jets - the case of PKS 2155-304

TL;DR

This paper introduces a time-dependent SSC model for blazar PKS 2155-304 that explains electron spectra through acceleration and losses, modeling flaring behavior and spectral evolution without extra parameters.

Contribution

A novel time-dependent SSC model incorporating stochastic and Fermi-I acceleration processes to explain blazar emission and variability.

Findings

Successfully models the 2006 H.E.S.S. outburst as jet fluctuations

Explains rising electron spectra needed for low-state SED fit

Provides insights into blazar flaring behavior

Abstract

A time-dependent Synchrotron Self Compton model (SSC) which is able to motivate the used electron spectra of many SSC models as a balance of acceleration and radiative losses is introduced. Using stochastic acceleration as well as Fermi-I processes even electron spectra with a rising part can be explained, which are mandatory to fit the lowstate spectral energy distribution (SED) of PKS 2155-304 as constrained from Fermi LAT observations. Due to the time resolution the outburst of PKS 2155-304 observed by H.E.S.S. in 2006 can be modelled selfconsistently as fluctuations along the jet axis without introducing new sets of parameters. The model makes the time evolution of the SED also accessible. Hence giving new insights into the flaring behavior of blazars.