Large scale extragalactic jets powered by very-high-energy gamma rays

by Dmitry SEMIKOZ (MPI Munich)

Thursday 28 Feb 2002, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

Recent Chandra observations of large scale (100 kpc) extragalactic jets in active galactic nuclei have puzzled the astrophysical community. By conventional estimates multi-TeV electrons needed to explain X-ray emission from the jets should lose all their energy on distance scales of the order of 1 kpc. It is usually supposed that electrons are continuously 'reaccelerated' all over the jet length in relativistic shocks (which means that some hundreds of identical shocks should follow each other over the length of the jet in order to explain X-ray data!). In this talk I shall discuss a principally different model in which 100 TeV electrons are produced all over the length of the jet through effective development of the electromagnetic cascade initiated by extremely high energy gamma-rays (E > 1e17 eV) interacting with CMBR and other soft photon backgrounds. This model can also provide a mechanism for the production of Ultra High Energy Cosmic Rays in active galactic nuclei.