PT Journal
AU Pierre Auger Collaboration (Abreu, Pea
   Pastor, S
TI Constraints on the origin of cosmic rays above 10^18 eV from large-scale anisotropy searches in data of the Pierre Auger Observatory
SO Astrophysical Journal Letters
JI Astrophys. J. Lett.
PY 2013
BP L13 - 8pp
VL 762
IS 1
DI 10.1088/2041-8205/762/1/L13
LA English
DE astroparticle physics; cosmic rays
AB 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 reported. For the first time, these large-scale anisotropy searches are performed as a function of both the right ascension and the declination and expressed in terms of dipole and quadrupole moments. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Upper limits on dipole and quadrupole amplitudes are derived under the hypothesis that any cosmic ray anisotropy is dominated by such moments in this energy range. These upper limits provide constraints on the production of cosmic rays above 10(18) eV, since they allow us to challenge an origin from stationary galactic sources densely distributed in the galactic disk and emitting predominantly light particles in all directions.
ER