Il Nuovo Cimento (1955-1965)

, Volume 8, Supplement 2, pp 466–471 | Cite as

Cosmic rays in intergalactic space

  • F. J. M. Farley
Origin Problem


Although the present discussion has been based on the model of Morrison Olbert and Rossi, the results are of more general application, and will apply whenever escape of cosmic rays from the Galaxy is envisaged. We have shown that, with present figures for the size and numbers of galaxies, the escape need not be a serious difficulty in any theory of acceleration, and it need not impose a high energy cut-off. Our relation between the strength or energy output of the accelerating mechanism and the expansion of the universe will be relevant whenever an extra-galactic origin is postulated for a part or the whole of the cosmic ray flux. If the source strength is sufficient to accelerate particles in galaxies with an equivalent characteristic time of order 100000 years, then it is reasonable to postulate cosmic rays throughout all space. If, on the other hand, the acceleration mechanism is insufficient for this, then we must suppose that the particles are confined to the galaxy.


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Copyright information

© Società Italiana di Fisica 1958

Authors and Affiliations

  • F. J. M. Farley
    • 1
  1. 1.Centre Européen de Recherches NucléxiresGeneva

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