Large scale distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory

Understand

A thorough search for large scale anisotropies in the distribution of arrival directions of cosmic rays detected above $10^{18}$ eV at the Pierre Auger Observatory is presented.

• This search is performed as a function of both declination and right ascension in several energy ranges above $10^{18}$ eV, and reported in terms of dipolar and quadrupolar coefficients.
• Within the systematic uncertainties, no significant deviation from isotropy is revealed.
• Assuming that any cosmic ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived.