Speaker
Dmitry Khangulyan
(MPI f. Kernphysik, Heidelberg)
Description
The energy spectra of TeV gamma-rays from blazars,
after being corrected for intergalatic absorption in the Extragalactic
Background Light, appear unusually hard. We show that the
internal absorption of gamma-rays caused by interactions with dense
narrow-band radiation fields in the vicinity of compact gamma-ray production
regions should lead to the formation of very hard gamma-ray spectra. Moreover,
synchrotron radiation of secondary electron-positron pairs (which has rather
unusual dependence on the production region bulk Lorenz factor) fits well
into observation data of some objects (e.g of distant blazar 1ES 1101-232).
Summary
The internal absorbition of VHE emission allows significant
relaxation of the current tight constraints on particle acceleration and
radiation models. The suggested scenario of formation of hard gamma-ray
spectra predicts detectable synchrotron radiation of secondary
electron-positron pairs which might require a revision of the current
``standard paradigm'' of spectral energy distributions of gamma-ray
blazars.
Author
Dmitry Khangulyan
(MPI f. Kernphysik, Heidelberg)
Co-authors
Felix Aharonian
(DIAS, Dublin)
Luigi Costamante
(HEPL/KIPAC, Stanford)
