Cosmic-ray (CR) acceleration at the shock created by the expanding cocoons around active galactic nuclei (AGNs) is studied. It is shown that above the energy 10~(18) eV the overall energy spectrum of CRs, produced during the AGN evolution and released in the intergalactic space, has the form N ∝ ∈~(-γ), with γ ≈ 2.6, which extends up to ∈_(max) ～10~(20) eV. It is concluded that cocoons shocks have to be considered as a main source of extragalactic CRs, which together with Galactic supernova remnants provide the observed CR spectrum.
展开▼
