Document Type
Article
Publication Date
8-24-2022
Department
Department of Physics
Abstract
A promising energy range to look for angular correlations between cosmic rays of extragalactic origin and their sources is at the highest energies, above a few tens of EeV (1 EeV 1018 eV). Despite the flux of these particles being extremely low, the area of ∼3000 km2 covered at the Pierre Auger Observatory, and the 17 yr data-taking period of the Phase 1 of its operations, have enabled us to measure the arrival directions of more than 2600 ultra-high-energy cosmic rays above 32 EeV. We publish this data set, the largest available at such energies from an integrated exposure of 122,000 km2 sr yr, and search it for anisotropies over the 3.4π steradians covered with the Observatory. Evidence for a deviation in excess of isotropy at intermediate angular scales, with ∼15° Gaussian spread or ∼25° top-hat radius, is obtained at the 4σ significance level for cosmic-ray energies above ∼40 EeV.
Publication Title
Astrophysical Journal
Recommended Citation
Abreu, P.,
Aglietta, M.,
Albury, J.,
Allekotte, I.,
Almeida Cheminant, K.,
Almela, A.,
Fick, B.,
Nitz, D.,
Norwood, I.,
Puyleart, A.,
&
et. al.
(2022).
Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory.
Astrophysical Journal,
935(2).
http://doi.org/10.3847/1538-4357/ac7d4e
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/16404
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© 2022. The Author(s). Published by the American Astronomical Society. Publisher’s version of record: https://doi.org/10.3847/1538-4357/ac7d4e