The origin of cosmic rays in spiral galaxies

Abstract

The problem of the origin and distribution of cosmic rays in the Galaxy is introduced by summarizing the literature on the radio and γ-ray studies of the Galaxy, discussing the propagation of cosmic rays in the interstellar medium, and listing the observed properties of cosmic rays. The localization of cosmic-ray electrons to their parent galaxies is an indicator that processes leading to cosmic-ray production may be common to galaxies like our own. The studies of external galaxies are therefore relevant to our own and have the advantage of better perspective.