Possible sources of ultrahigh-energy cosmic protons

The arrival directions of showers with energies above 3.2·10¹⁹ eV, recorded by the Akeno and AGASA detectors, are analyzed. Their distributions over the celestial sphere are compared with the distributions of possible sources of protons of such high energies. An analysis using three standard deviations of uncertainty in the determination of the arrival directions of the showers shows that the sources of the protons initiating the showers are nuclei of active galaxies with red shifts z≤0.0092, i.e. their distance from us does not exceed 40 Mpc, assuming the Hubble constant is H=75 km/s·Mpc. Pis’ma Zh. éksp. Teor. Fiz. 64, No. 2, 71–75 (25 July 1996)