Science with the New Generation of High Energy Gamma-Ray Experiments #6

Session

Extragalactic Sources 2

9 Oct 2008, 16:50

Padova

10. The blazar sequence: prospects for GeV and TeV observations

Dr Fabrizio Tavecchio (INAF)

09/10/2008, 16:50

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...

1. Gamma ray emission and particle acceleration in galaxy clusters

Dr Gianfranco Brunetti (INAF-IRA, Bologna)

09/10/2008, 17:20

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...

8. Constraints on Extragalactic Background Light from Cherenkov telescopes: status and perspectives for the next 5 years

Daniel Mazin (IFAE, Barcelona)

09/10/2008, 18:10

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...