Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

PIERRE AUGER COLLABORATION, DIEGO RAVIGNANI

ASTROPARTICLE PHYSICS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2011 vol. 34 p. 627 - 639

0927-6505

We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5 × 1017 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.