Speaker
Description
Previous work on time-dependent shock-acceleration and radiation
transfer in relativistic jets has successfully reproduced many
spectral variability features of blazars if flaring activity is
mediated by increasingly efficient diffusive shock acceleration.
However, flaring events exhibiting a significant increase of the
Compton dominance, or even "orphan" gamma-ray flares, are very
difficult to reproduce in this manner, suggesting that an enhancement
of an external radiation field for Compton scattering may be responsible
for the gamma-ray flaring. This work therefore investigates the signatures
of a synchrotron mirror model in which the synchrotron emission of
electrons accelerated by a mildly relativistic shock traveling along
the jet, is reflected by a cloud, and the reflected synchrotron
radiation acts as target photon field for enhanced Compton scattering
further down the jet. The model is applied to recent flaring events
exhibiting a significant enhancement of the Compton dominance in
3C279, and the expected spectral variability features are investigated
in detail.
