Modelling rapid TeV variability of PKS 2155-304

TL;DR

This paper models the rapid TeV variability of PKS 2155-304 using a multi-component jet scenario with synchrotron self-Compton processes, explaining observed flaring events and spectral features.

Contribution

It introduces a multi-component jet model with detailed particle evolution to explain rapid TeV variability in PKS 2155-304, incorporating light travel time effects.

Findings

Multiple jet components can reproduce rapid TeV flares.

Absorption due to pair creation is negligible in this scenario.

A simple SSC model suffices to explain the variability.

Abstract

We present theoretical modelling for the very rapid TeV variability of PKS 2155--304 observed recently by the H.E.S.S. experiment. To explain the light-curve, where at least five flaring events were well observed, we assume five independent components of a jet that are characterized by slightly different physical parameters. An additional, significantly larger component is used to explain the emission of the source at long time scales. This component dominates the emission in the X-ray range, whereas the other components are dominant in the TeV range. The model used for our simulation describes precisely the evolution of the particle energy spectrum inside each component and takes into account light travel time effects. We show that a relatively simple synchrotron self-Compton scenario may explain this very rapid variability. Moreover, we find that absorption of the TeV emission inside the components due to the pair creation process is negligible.