Correlation of the highest energy cosmic rays with nearby extragalactic o bjects

THE PIERRE AUGER COLLABORATION (P. HANSEN PERTENECE A LA COLABORACION-ORDEN ALFABETICO)

SCIENCE

AMER ASSOC ADVANCEMENT SCIENCE

Año: 2007 vol. 318 p. 939 - 943

0036-8075

Using data collected at the Pierre Auger Observatory during the past 3.7 years, wedemonstrated a correlation between the arrival directions of cosmic rays with energy above 6 × 1019 electron volts and the positions of active galactic nuclei (AGN) lying within ~75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these cosmic rays with at least a 99% confidence level from a prescribed a priori test. The correlation we observed is compatible with the hypothesis that the highest-energy particles originate from nearby extragalactic sources whose flux has not been substantially reducedby interaction with the cosmic background radiation. AGN or objects having a similar spatial distribution are possible sources.