Detection of a cosmic ray with measured energy well beyond the expected spectral cutoff due to cosmic microwave radiation

Collaboration
Oct, 1994
7 pages
Published in:
  • Astrophys.J. 441 (1995) 144-150
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Abstract: (ADS)
We report the detection of a 51 Joule (3.2±0.9×10203.2 \pm 0.9 \times 10^{20} eV) cosmic ray by the Fly's Eye air shower detector in Utah. This is substantially greater than the energy of any previously reported cosmic ray. A Greisen-Zatsepin-Kuz'min cutoff of the energy spectrum (due to pion photoproduction energy losses) should occur below this energy unless the highest energy cosmic rays have traveled less than approximately 30 Mpc. The error box for the arrival direction in galactic coordinates is centered on b=9.6°b = 9.6\degree , l=163.4°l = 163.4\degree. The particle cascade reached a maximum size near a depth of 815 g/sq cm in the atmosphere, a depth which does not uniquely identify the type of primary particle.
Note:
  • Oh-My-God particle
  • Oh-My-God particle
  • Oh My God particle