LARGE-SCALE DISTRIBUTION OF ARRIVAL DIRECTIONS OF COSMIC RAYS DETECTED ABOVE 10 18 eV AT THE PIERRE AUGER OBSERVATORY

THE PIERRE AUGER COLLABORATION(495 AUTHORS IN ALPHABETICAL ORDER); GARCIA, B. (495 AUTHORS IN ALPHABETICAL ORDER))

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES

IOP PUBLISHING LTD

Lugar: Londres; Año: 2012 vol. 203 p. 1 - 20

0067-0049

A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declinationand right ascension in several energy ranges above 1018 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. These upper limits allow us to test the origin of cosmic rays above 1018 eV fromstationary Galactic sources densely distributed in the Galactic disk and predominantly emitting light particles in alldirections.