Determining the Spectra of Spatially Distributed Evolutionary Sources of Extragalactic Ultrahigh Energy Cosmic Rays

Abstract

A study is performed of the effect the cosmological evolution and spatial distribution of sources have on solving the inverse problem of determining the spectra of ultrahigh energy cosmic ray sources. The solution allows for the propagation and energy losses of protons and nuclei in the expanding Universe. It is established that active galactic nuclei are the most probable sources of ultrahigh energy cosmic rays.