Search for first harmonic modulation in the right ascension distribution of cosmic rays detected at the Pierre Auger Observatory


Abstract:

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. © 2011 Published by Elsevier B.V.

Año de publicación:

2011

Keywords:

  • Large scale anisotropies
  • Ultra-high energy cosmic rays
  • Pierre auger observatory

Fuente:

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