Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory

S. J. SCIUTTO; THE PIERRE AUGER COLLABORATION.

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2022 vol. 935

0004-637X

A promising energy range to look for angular correlations between cosmic rays of extragalactic origin and theirsources is at the highest energies, above a few tens of EeV (1 EeV ≡ 1018 eV). Despite the flux of these particlesbeing extremely low, the area of ∼3000 km2 covered at the Pierre Auger Observatory, and the 17 yr data-takingperiod of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultrahigh-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from anintegrated exposure of 122,000 km2 sr yr, and search it for anisotropies over the 3.4π steradians covered with theObservatory. Evidence for a deviation in excess of isotropy at intermediate angular scales, with ∼15° Gaussianspread or ∼25° top-hat radius, is obtained at the 4σ significance level for cosmic-ray energies above ∼40 EeV.