Cosmic ray anisotropies to 5 PeV

Understand

Several large cosmic ray (CR) detectors have recently provided data on the arrival directions of CR, which taken together with previous data recorded over many decades allow the amplitgude and phase of the first harmonic to be derived with reasonable precision and up to higher energies.

• We find a high degree of consistency amongst the various measurements.
• The new data indicate that at an energy above ~0.1 PeV a change of the CR anisotropy sets in.
• The amplitude of the first harmonic, which rises to 3 TeV, then diminishes and begins to rise again.