2000/11/20 by G. Ghisellini, Gabriele Ghisellini, Ghisellini, Gabriele
Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Neutrino Physics Research #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0011356
10 pages, 4 figures, uses newpasp.sty (included). Invited talk at the meeting: Blazar Demographics and Physics, ASP Conf. Series, P. Padovani and C. M. Urry eds., in press
arxiv created 2000/11/20 · openalex publication_date 2000/11/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The radiation observed by blazars is believed to originate from the transformation of bulk kinetic energy of relativistic jets into random energy. A simple way to achieve this is to have an intermittent central power source, producing shells of plasma with different bulk Lorentz factors. These shells will collide at some distance from the center, producing shocks and then radiation. This scenario, called internal shock model, is thought to be at the origin of the gamma-rays observed in gamma-ray bursts and can work even better in blazars. It accounts for the observed key characteristics of these objects, including the fact that radiation must be preferentially produced at a few hundreds of Schwarzschild radii from the center, but continues to be produced all along the jet. At the kpc scale and beyond, the slowly moving parts of a (straight) jet can be illuminated by the beamed radiation of the core, while the fast parts of the jet will see enhanced cosmic microwave radiation. In both cases the Inverse Compton process can be the dominant radiation process, leading to a copious production of high energy (X-rays and beyond) radiation in both radio loud quasars and radio-galaxies.