Quasars as sources of ultrahigh-energy cosmic rays

The results are presented that were obtained by analyzing arrival directions for cosmic rays that the Yakutsk array for studying extensive air showers recorded between 1974 and 2002 in the energy region E₀ ≥ 5 × 10¹⁷ eV for zenith angles in the region θ ≤ 60°. It is shown that quasars for which the red shift lies in the region z ≤ 2.5 can be sources of these cosmic rays. Ordered structures are observed in the disposition of quasars and in the cosmic-ray arrival directions. These structures can be associated in one way or another with the large-scale structure of the Universe.