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

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.Comment: 6 pages, 2 figures; to appear in the proceedings of the conference: "High Energy Phenomena in Relativistic Outflows (HEPRO) II", held in Buenos Aires, Argentina, October 26-30 2009 (IJMPD