Active Galactic Nuclei as potential Sources of Ultra-High Energy Cosmic Rays by Frank M. Rieger. on Tuesday 22 November

Active Galactic Nuclei (AGNs) and their relativistic jets belong to the most

promising class of ultra-high-energy cosmic ray (UHECR) accelerators. This

compact review summarises basic experimental findings by recent instruments,

and discusses possible interpretations and astrophysical constraints on source

energetics. Particular attention is given to potential sites and mechanisms of

UHECR acceleration in AGNs, including gap-type particle acceleration close to

the black hole, as well as first-order Fermi acceleration at trans-relativistic

shocks and stochastic shear particle acceleration in large-scale jets. It is

argued that the last two represent the most promising mechanisms given our

current understanding, and that nearby FR~I type radio galaxies provide a

suitable environment for UHECR acceleration.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.12202v1