Ever since the existence of cosmic rays with individual energies of several Joules was established in the 1960s, speculation has raged as to whether cosmic particles of mean energy of 2 Joules are created in our Milky Way or in distant extragalactic objects.
Scientific Highlights
Cosmic rays are mostly charged particles that reach Earth from outer space.
The Pierre Auger Collaboration has investigated the constraining power of the cosmic ray spectrum and composition measurements with respect to the properties of the possible sources.
The Pierre Auger Collaboration has searched for the possible presence of photons with energies exceeding 1018 eV in the flux of cosmic rays arriving at Earth.
When an ultrahigh-energy cosmic ray impacts the Earth’s atmosphere, it can generate an enormous cascade of billions of energetic particles capable of reaching the ground.
One of the most pressing mysteries in astroparticle physics is the composition and origin of cosmic rays at energies around 1 EeV = 1018 eV.
