The Akeno Giant Air Shower Array (AGASA) is a very large surface array designed to study the origin of

ultra-high-energy cosmic ray In astroparticle physics, an ultra-high-energy cosmic ray (UHECR) is a cosmic ray with an energy greater than 1 EeV (1018 electronvolts, approximately 0.16 joules), far beyond both the rest mass and energies typical of other cosmic ray partic ...

s. Located in the town of Akeno in Yamanashi prefecture, Japan, it covers an area of 100 km² and consists of 111

surface A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is t ...

detectors and 27

muon A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As wi ...

detectors. Array experiments such as this one are used to detect air shower particles. The array is operated by the

Institute for Cosmic Ray Research The Institute for Cosmic Ray Research (ICRR) of the University of Tokyo (東京大学宇宙線研究所 ''Tōkyōdaigaku Uchūsen Kenkyūsho'') was established in 1976 for the study of cosmic rays. The gravitational wave studies group is currently ...

University of Tokyo , abbreviated as or UTokyo, is a public research university located in Bunkyō, Tokyo, Japan. Established in 1877, the university was the first Imperial University and is currently a Top Type university of the Top Global University Project by ...

at the

Akeno Observatory Akeno Observatory is a cosmic ray observatory located in Akeno, a town in Yamanashi prefecture, Japan. The observatory is run by the Institute for Cosmic Ray Research (ICRR), based at the University of Tokyo. Akeno Observatory features AGASA, the ...

Results

The results from AGASA were used to calculate the energy spectrum and

anisotropy Anisotropy () is the property of a material which allows it to change or assume different properties in different directions, as opposed to isotropy. It can be defined as a difference, when measured along different axes, in a material's physic ...

of cosmic rays. The results helped to confirm the existence of ultra-high energy cosmic rays ( >), such as the so-called " Oh-My-God" particle that was observed by the Fly's Eye experiment run by the

University of Utah The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of De ...

. The

Telescope Array An astronomical interferometer or telescope array is a set of separate telescopes, mirror segments, or radio telescope antennas that work together as a single telescope to provide higher resolution images of astronomical objects such as stars, ne ...

, a merger of the AGASA and High Resolution Fly's Eye (HiRes) groups, and the

Pierre Auger Observatory The Pierre Auger Observatory is an international cosmic ray observatory in Argentina designed to detect ultra-high-energy cosmic rays: sub-atomic particles traveling nearly at the speed of light and each with energies beyond 1018 eV. In Ear ...

have improved on the results from AGASA by building larger, hybrid detectors and collecting greater quantities of more precise data.

References

External links

AGASA

High Resolution Fly's Eye
High energy particle telescopes Cosmic-ray experiments {{particle-stub

Results

See also

References

External links