TeV signatures of compact UHECR accelerators

We numerically study particle acceleration by the electric field induced near the horizon of a rotating supermassive (M ∼ 109-10 10M(⊙)) black hole embedded in the magnetic field B. We find that acceleration of protons to the energy E ∼ 1020 eV is possible only at extreme values of M and B. We also find that the acceleration is very inefficient and is accompanied by a broad-band MeV-TeV radiation whose total power exceeds the total power emitted in ultrahigh energy cosmic rays (UHECRs) at least by a factor of 1000. This implies that if O(10) nearby quasar remnants were sources of proton events with an energy E > 1020 eV, then each quasar remnant would, e.g. overshine the Crab Nebula by more than two orders of magnitude in the TeV energy band. Recent TeV observations exclude this possibility. A model in which O(100) sources are situated at 100-1000 Mpc is not ruled out and can be experimentally tested by present TeV γ-ray telescopes. Such a model can explain the observed UHECR flux at moderate energies E ≈ (4-5) × 1019 eV. © 2005 Pleiades Publishing, Inc.SCOPUS: ar.j