THE ORIGINS OF HIGH-ENERGY COSMIC-RAYS

Our current understanding of acceleration processes for Galactic and extragalactic cosmic rays is briefly reviewed. Shock acceleration in supernova remnants remains the most favored process for cosmic rays up to the ''knee'' of the all-particle total energy spectrum at 10(14)-10(15) eV. The highest energy particles are almost certainly extragalactic, and the most favored sources are associated with active galactic nuclei in one way or another. The intermediate region between rigidities of 10(14) and 10(18) V is more difficult to understand, although a galactic origin is preferred at present. The problem of making a smooth join in the spectrum at the knee suggests that these particles should not be considered to be independent of those at lower energies.