Schedule Oct 02, 2009
Particle Acceleration in a SSC Model
Matthias Weidinger (Univ. Wuerzburg)

A fully self-consistent extension to the SSC model with particle acceleration due to shock and stochastic acceleration (Fermi-I and Fermi-II-Processes respectively) in a twozone-SSC model, i.e. two spatially homogenous and isotropic emitting spheres, is presented. The emphasis lies on the influence of the implemented acceleration processes on the electron spectra in the twozone-SSC model. We find that shock acceleration in competition with radiative synchrotron losses of the electrons leads to falling powerlaw electron spectra depending only on the ratio of the timescale of the catastrophic electron escape losses and the intrinsic acceleration timescale itself. Whereas stochastic processes leading to the exponential cutoff at high electron energy regimes and to rising powerlaw specta at small electron Lorentz-factors $gamma$ thus explaining recent observational data e.g. from PKS2155 observed by FERMI in Aug/Sept 2008. Concluding the validity of the implemented hard-sphere approximation of the plasma instabilities and the limits of such a simple acceleration model (only two well known acceleration mechanisms) for a highly relativistc jet system shall be discussed.

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