The Large Magellanic Cloud as a source of the highest energy cosmic rays

Abstract

The Pierre Auger Observatory has published properties of the 100 highest-energy cosmic ray events (to energies above 100 EeV) which it recorded over a 17 year period. We have examined the directional properties of these events and have taken particular note of the most energetically extreme events. We find that the most energetic events have directions which are grouped in a non-random way at the 1 % level. There is an apparent clustering in a limited region of the sky. Close to that direction is found Centaurus A, which has long been considered as a source of such particles, but we also note that a close-by dwarf galaxy, the Large Magellanic Cloud (LMC) is closer in angular terms. We examine the possibility that the LMC might be a source of observed cosmic rays at the highest energies.