corner
corner
APS » Journals » Phys. Rev. Lett. » Volume 77 » Issue 6
< Previous Article | Next Article >

Phys. Rev. Lett. 77, 1000–1003 (1996)

Possible Clustering of the Most Energetic Cosmic Rays within a Limited Space Angle Observed by the Akeno Giant Air Shower Array

Download: PDF (109 kB) Buy this article Export: BibTeX or EndNote (RIS)

N. Hayashida1, K. Honda2, M. Honda1, N. Inoue3, K. Kadota4, F. Kakimoto4, K. Kamata5, S. Kawaguchi6, N. Kawasumi2, Y. Matsubara7, K. Murakami8, M. Nagano1, H. Ohoka1, N. Sakaki1, N. Souma3, M. Takeda4, M. Teshima1, I. Tsushima2, Y. Uchihori1, S. Yoshida1, and H. Yoshii9
1Institute for Cosmic Ray Research, University of Tokyo, Tokyo 188, Japan
2Faculty of Education, Yamanashi University, Kofu 400, Japan
3Department of Physics, Saitama University, Urawa 338, Japan
4Department of Physics, Tokyo Institute of Technology, Tokyo 152, Japan
5Nishina Memorial Foundation, Komagome, Tokyo 188, Japan
6Faculty of General Education, Hirosaki University, Hirosaki 036, Japan
7Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-01, Japan
8Nagoya University of Foreign Studies, Nissin, Aichi 470-01, Japan
9Department of Physics, Ehime University, Matsuyama 790, Japan

Received 12 March 1996; published in the issue dated 5 August 1996

Accumulated data of the Akeno Giant Air Shower Array (AGASA) indicate that arrival directions of a significant fraction of extremely high energy cosmic rays (EHECR) are uniformly distributed over the observable sky. However, three pairs of showers with angular separation of less than 2.5° within the pair are observed among the 36 events above 40 EeV ( 4×1019eV), corresponding to a chance probability of 2.9% from uniform distribution. It should be noted that two pairs of them are observed to be within 2.0° of the supergalactic plane.

© 1996 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevLett.77.1000
DOI:
10.1103/PhysRevLett.77.1000
PACS:
98.70.Sa, 95.85.Ry, 98.65.Cw
 
< Previous Article | Next Article >