Energy determination in the Akeno Giant Air Shower Array experiment

2002/09/30 by M. Takeda, N. Sakaki, Н. Сакаки +32 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #Radio Astronomy Observations and Technology #astro-ph

paper · pdf · doi:10.1016/s0927-6505(02)00243-8

published as Astropart.Phys. 19 (2003) 447-462 · accepted to Astroparticle Physics, 29pages, 17+1 figures, elsart.cls The AGASA exposure is 5.1x10^16 m2 sr s until July 2002

arxiv created 2002/11/13 · openalex publication_date 2003/05/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Using data from more than ten-years of observations with the Akeno Giant Air Shower Array (AGASA), we published a result that the energy spectrum of ultra-high energy cosmic rays extends beyond the cutoff energy predicted by Greisen, and Zatsepin and Kuzmin. In this paper, we reevaluate the energy determination method used for AGASA events with respect to the lateral distribution of shower particles, their attenuation with zenith angle, shower front structure, delayed particles observed far from the core and other factors. The currently assigned energies of AGASA events have an accuracy of ±25% in event-reconstruction resolution and ±18% in systematic errors around 10²⁰eV. This systematic uncertainty is independent of primary energy above 10¹⁹eV. Based on the energy spectrum from 10^14.5eV to a few times 10²⁰eV determined at Akeno, there are surely events above 10²⁰eV and the energy spectrum extends up to a few times 10²⁰eV without a GZK-cutoff.

Citations

• A measurement of the cosmic ray spectrum and composition at the knee
• Extension of the Cosmic-Ray Energy Spectrum beyond the Predicted Greisen-Zatsepin-Kuz'min Cutoff

Cited by

• On the possibility of primary identification of individual cosmic ray showers