PT Journal
AU Pierre Auger Collaboration (Abreu, Pea
   Pastor, S
TI Search for first harmonic modulation in the right ascension distribution of cosmic rays detected at the Pierre Auger Observatory
SO Astroparticle Physics
JI Astropart Phys.
PY 2011
BP 627
EP 639
VL 34
IS 8
DI 10.1016/j.astropartphys.2010.12.007
LA English
DE Ultra-high energy cosmic rays; Large scale anisotropies; Pierre Auger Observatory
AB We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5 x 10(17) eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.
ER