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.
| Originalsprog | Engelsk |
|---|---|
| Artikelnummer | L18 |
| Tidsskrift | Astrophysics Journal Letters |
| Vol/bind | 886 |
| Udgave nummer | 1 |
| Antal sider | 6 |
| ISSN | 2041-8205 |
| DOI | |
| Status | Udgivet - 20 nov. 2019 |
Emneord
- astro-ph.HE
- hep-ex
- hep-ph