Dr
Fabrizio Tavecchio
(INAF)
10/9/08, 4:50 PM
I discuss the concept and the consequences of the so-called "blazar sequence", connecting the position of the peaks in the spectral energy distribution of blazars with the emitted luminosity. I also present a recent revision of the theoretical basis of the blazar sequence, which, contrary to the simplest interpretation, predicts a large population of low-power "red" blazars and possibly the...
Dr
Gianfranco Brunetti
(INAF-IRA, Bologna)
10/9/08, 5:20 PM
The presence of non-thermal components in galaxy clusters, like relativistic electrons and magnetic fields, is demonstrated by radio observations that detect large scale synchrotron emission from the inter-galactic-medium of a fraction of massive clusters. On the other hand present observations can provide only upper limits to the energy content of relativistic protons.
GLAST has the...
Daniel Mazin
(IFAE, Barcelona)
10/9/08, 6:10 PM
Very high energy (VHE, E > 30 GeV) gamma-rays are absorbed via interaction with low-energy photons from the
extragalactic background light (EBL) if the involved photon energies are above the threshold for electron-positron pair creation. The VHE gamma-ray absorption,
which is energy dependent and increases strongly with redshift, distorts the VHE energy spectra observed from distant...
