The observed anisotropy of arrival directions of incoming cosmic ray particles with energy above 6 . 1019 eV is one of the most important results of the Pierre Auger Observatory. Such particles are very rare and during 50 years of their measurement at different observatories only few tens of them were detected. Because of their extremely large energy, that is many orders of magnitude larger than what humans can produce in laboratories, their existence is very puzzling and no existing astrophysical theory can fully explain their production. The full text >>
