Ultra-High Energy Cosmic Rays from Quasar Remnants

Abstract

One of the models recently proposed to explain the origin of the ultra high energy cosmic rays assumes that these particles may be accelerated by the electromotive force around presently inactive quasar remnants. We study predictions for large and small scale ultra high energy cosmic ray arrival direction anisotropies in a scenario where the particles are injected with a mono-energetic spectrum by a discrete distribution of such sources. We find that known quasar remnants are typically distributed too anisotropically to explain the isotropic ultra high energy cosmic ray flux except in the unrealistic case where extragalactic magnetic fields of ~0.1 microGauss extend over many Mpc.