Arrival Directions of the Most Energetic Cosmic Rays

Abstract

In this Letter we examine the arrival directions of the most energetic cosmic rays $(E>2\ifmmode\times\else\texttimes\fi{}{10}^{19}\mathrm{eV})$ detected by several air shower experiments. We find that data taken by different air shower arrays show positive correlations, indicating a nonuniform arrival direction distribution. We also find that the events with energy $>4\ifmmode\times\else\texttimes\fi{}{10}^{19}\mathrm{eV}$ exhibit a correlation with the general direction of the supergalactic plane, where a large number of potential sources are located. If confirmed by data from other experiments our results would support models for the extragalactic origin of the highest energy cosmic rays.