29th International Cosmic Ray Conference Pune (2005) 00, 101-104
Clusters of Cosmic Rays above 4.1019 eV A.A. Mikhailov, N.N. Efremov. Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Ave., 677980 Yakutsk, Russia
Presenter: A. Mikhailov (
[email protected]), rus-mikhailov-AA-abs2-HE14-poster Arrival directions of cosmic rays with the energy E>4.1019 eV are analyzed on the basis of the Yakutsk and AGASA extensive air shower arrays. It is supposed that the clusters can be formed as a result of fragmentation of superheavy nuclei. The consequences of this supposition compare with experimental data. Part of clusters with E>2.1019 eV correlate with the nearest pulsars. The new effect is found – clusters intensify a feature of cosmic rays distribution.
1. Introduction By using AGASA array data in the region of ultrahigh energy E>4.1019 eV, 7 clusters have been found [1]: 1 triplet and 6 doublets. The distance between showers in the clusters is 4.1019 eV [1]. 1863 EAS’ with zenith angles < 60° for the period 1974 to 2002 by Yakutsk data have been analyzed. Among them we found 5157 doublets (clusters with the large number of particles are not considered). The distance between EAS’ in the doublets is E2 arrives first to the Earth (t1E2 arrives second (t1>t2). The shower energy in experimental data is determined with some error, therefore it is difficult to determine what of doublet particles really has the higher energy. In this connection, the doublets having particles with energies close to one another within the limits of lg(E1/E2)E2 arrives first to the Earth (t1E2 arrives second (t1>t2). As can be seen, at E2.1019 eV the number of doublets, whose particle with E1>E2 arrives first, (t1E2 arrives first (t1E2 arrives second (t1>t2).• - Yakutsk, v AGASA.
N um be r o f c lu ste rs
1 35
b
30 25 20 15 10 5 0
5
-60
-30
0
30
60
90
c
Thus, in spite of large statistical errors in the 0 determination of R the conclusion can be made, -60 -30 0 30 60 90 G a la c ti c la ti tud e , de g that the doublets at E>2.1019 eV are most probably formed as a result of superheavy nuclei Fig.2. The doublet distribution in galaxy latitude for decay. Probably, the doublets at E2.10 eV. 19.3 H9 k ! eV. Next, we will attempt to clarify origin doublets at E
