Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Diffusion of the highest energy cosmic rays from Virgo


The origin of the predominant particle component of cosmic rays is still undecided although at ‘low’ energies (E109–1010 eV) γ-ray data provide circumstantial evidence in favour of an origin in galactic sources1. The galactic magnetic field deflects trajectories, at least until about 1018 eV, and almost completely destroys any relationship between the directions from which cosmic rays arrive and the directions to their sources, making the elucidation of origins a problem. Above 1018 eV, if the primary cosmic rays are mainly protons, as would be expected and as is claimed3, then the absence of large anisotropies associated with the galactic plane strongly suggests that the particles are from extragalactic sources. If they are extragalactic and their sources are distributed widely in the Universe then, because of interactions between the protons and the photons of the 2.7 K relict radiation, the observed spectrum should steepen considerably above several times 1019 eV. However, the opposite appears to be happening: the measured spectrum flattens above about 1019 eV (refs 4–6) (see Fig. 2). Several suggestions have been made to account for this paradox, in each case the idea being to generate in extragalactic space a production spectrum which is so ‘flat’ that even after energy losses are taken into account, the resulting spectrum at the Earth has the characteristic observed flattening (for example ref. 7). Here we put forward an alternative model where the observed spectral shape arises in a rather natural way, being due to propagation characteristics in the local supercluster, the bulk of the very energetic particles having originated in its central region.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Dodds, D., Strong, A. W. & Wolfendale, A. W. Mon. Not. R. astr. Soc. 171, 569 (1975).

    Article  ADS  CAS  Google Scholar 

  2. Barrett, M. L. et al. Proc. 15th Int. Cosmic Ray Conf. (Plovdiv) 8, 172 (1977).

    ADS  Google Scholar 

  3. Pollock, A. M. T., Reid, R. J. O. & Watson, A. A. Proc. 15th Int. Cosmic Ray Conf. (Plovdiv) 2, 292 (1977).

    ADS  Google Scholar 

  4. Krasilnikov, D. D. et al. Proc. 15th Int. Cosmic Ray Conf. (Plovdiv) 8, 159 (1977).

    ADS  Google Scholar 

  5. Cunningham, G. et al. Proc. 15th Int. Cosmic Ray Conf. (Plovdiv) 2, 303 (1977).

    ADS  Google Scholar 

  6. Diminstein, O. S. et al. Proc. 15th Int. Cosmic Ray Conf. (Plovdiv) 8, 154 (1977).

    ADS  Google Scholar 

  7. Wdowczyk, J. & Wolfendale, A. W. J. Phys. A9, L197 (1976).

    ADS  CAS  Google Scholar 

  8. Strong, A. W., Wdowczyk, J. & Wolfendale, A. W. J. Phys. A7, 1767 (1974).

    ADS  CAS  Google Scholar 

  9. Stecker, F. W. Phys. Rev. Lett. 21, 1016 (1968).

    Article  ADS  CAS  Google Scholar 

  10. Stecker, F. W. Comments Astrophys. 7, 4 (1978).

    Google Scholar 

  11. Ginzburg, V. L. & Syrovatsky, S. I. The Origin of Cosmic Rays (Pergamon, London, 1964).

    Book  Google Scholar 

  12. Forman, W. et al. Astrophys. J. 225, L1 (1977).

    Article  ADS  Google Scholar 

  13. Kiraly, P. et al. Nuovo Cim. (in the press).

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Wdowczyk, J., Wolfendale, A. Diffusion of the highest energy cosmic rays from Virgo. Nature 281, 356–357 (1979).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing