Name of the Speaker(s):Marek Sikora
Institution: N. Copernicus Astronomical Center
Polish Academy of Sciences
Title of the communication: Do we have the theory of gamma-ray blazars?
Preliminary abstract (12 lines max.):
We show that the high energy spectra of
gamma-ray loud
blazars cannot be explained by any simple
version of existing models.
The ``differential'' pair models fail to
reproduce flat X-ray spectra, the hadronic
models fails to reproduce steep gamma-ray
spectra, the synchrotron-self-Compton
models require too low magnetic energy
densities, and
the external-radiation-Compton models
predict too much soft X-rays.
We argue that soft X-ray excesses, which
are predicted by us to accompany hard
X-ray and gamma-ray spectra in all models,
can be avoided only in a case of efficient
collective plasma processes keeping
electrons at relativistic temperatures,
or negligible pair production in a jet.