Extension of the Cosmic-Ray Energy Spectrum Beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff

@article{Takeda1998ExtensionOT,
  title={Extension of the Cosmic-Ray Energy Spectrum Beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff},
  author={Masahiro Takeda and N. Hayashida and Ken Honda and Naoko Inoue and K. Kadota and Fumio Kakimoto and Keigo Kamata and S. Kawaguchi and Yoshiya Kawasaki and Norio Kawasumi and Hidemitsu Kitamura and E. Kusano and Yutaka Matsubara and Kazuaki Murakami and Motohiko Nagano and D. Nishikawa and Hideyuki Ohoka and N. Sakaki and Makoto Sasaki and Kenji Shinozaki and N. Souma and Masahiro Teshima and Rodney H. Torii and Itsuro Tsushima and Yukio Uchihori and T. Yamamoto and Shigeru Yoshida and Hisashi Yoshii},
  journal={Physical Review Letters},
  year={1998},
  volume={81},
  pages={1163-1166}
}
The cosmic-ray energy spectrum above 10^{18.5} eV is reported using the updated data set of the Akeno Giant Air Shower Array (AGASA) from February 1990 to October 1997. The energy spectrum extends beyond 10^{20} eV and the energy gap between the highest energy event and the others is being filled up with recently observed events. The spectral shape suggests the absence of the 2.7 K cutoff in the energy spectrum or a possible presence of a new component beyond the 2.7 K cutoff. 

Figures from this paper

The Energy Spectrum Observed by the AGASA Experiment and the Spatial Distribution of the Sources of Ultra-High-Energy Cosmic Rays

Seven and a half years of continuous monitoring of giant air showers triggered by ultra-high-energy cosmic rays have been summarized recently by the AGASA collaboration. The resulting energy spectrum

Deep shower interpretation of the cosmic ray events observed in excess of the Greisen-Zatsepin-Kuzmin energy

We consider the possibility that the ultra-high-energy cosmic ray flux has a small component of exotic particles which create showers much deeper in the atmosphere than ordinary hadronic primaries.

Energy spectrum of ultra high energy cosmic rays

The construction of the southern site of the Pierre Auger Observatory is almost completed. Three independent measurements of the flux of the cosmic rays with energies larger than 1 EeV have been

The Highest-Energy Cosmic Rays

The search for the origin of cosmic rays with energies above 1018 eV has made considerable progress during the past few years. With new data from the High Resolution Fly's Eye experiment in Utah and

Status and prospects of the ultrahigh energy cosmic rays

This paper summarizes measurement results of the UHECR energy spectrum and arrival directions. Various scenarios trying to explain the flat AGASA spectrum (no GZK cutoff) are recalled. Recent HiRes

Energy spectrum and mass composition of high-energy cosmic rays

Primary cosmic rays above energies of about 100 TeV are investigated by observations of extensive air showers (EAS) using large area ground based detector installations for registering various

Ultra-high energy cosmic rays may come from clustered sources

Clustering of cosmic-ray sources affects the flux observed beyond the cutoff imposed by the cosmic microwave background and may be important in interpreting the AGASA, Fly's Eye, and HiRes data. The
...

References

SHOWING 1-10 OF 16 REFERENCES

1166 nd icxt ray r y ds n nd in ion aer ir er he d e r, r

  • Astrophy 199,
  • 1988

Astrophys. J. Suppl

  • Astrophys. J. Suppl
  • 1995

Astron

  • Astrophys. Suppl. 53
  • 1983

Astrophys. J. Prog. Theor. Phys. Astron. Astrophys. Nature

  • Astrophys. J. Prog. Theor. Phys. Astron. Astrophys. Nature
  • 1976

Proc. Suppl.) 28B

  • Proc. Suppl.) 28B
  • 1992

Nucl. Instr. and Meth. A

  • Nucl. Instr. and Meth. A
  • 1992

Astropart. Phys

  • Astropart. Phys
  • 1995

J. Phys. G:Nucl. Part. Phys

  • J. Phys. G:Nucl. Part. Phys
  • 1986