Abstract
We search for anisotropies in the arrival directions of cosmic rays (CRs) observed by the KASCADE-Grande air shower experiment. The analysis is based on public data of about 23.7 million events with reconstructed primary energies above 1 PeV. We apply a novel maximum-likelihood reconstruction method for the CR anisotropy that compensates for spurious anisotropies induced by local detector effects. We find no evidence for a large-scale dipole anisotropy in the data, consistent with official results based on the conventional east-west derivative method. On the other hand, a subset of CRs with a median energy of 33 PeV shows strong evidence for a medium-scale feature with an angular diameter of 40°. After accounting for the look-elsewhere effect, the post-trial significance of this medium-scale feature is at the level of 4σ.
| Original language | English |
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| Article number | L18 |
| Journal | Astrophysics Journal Letters |
| Volume | 886 |
| Issue number | 1 |
| Number of pages | 6 |
| ISSN | 2041-8205 |
| DOIs | |
| Publication status | Published - 20 Nov 2019 |