Modification of the Dipole in Arrival Directions of Ultra-high-energy Cosmic Rays due to the Galactic Magnetic Field
arXiv:2303.08766 · doi:10.1088/1475-7516/2023/12/016
Abstract
The direction and magnitude of the dipole anisotropy of ultra-high-energy cosmic rays with energies above 8 EeV observed by the Pierre Auger Observatory indicate their extragalactic origin. The observed dipole on Earth does not necessarily need to correspond to the anisotropy of the extragalactic cosmic-ray flux due to the effects of propagation in the Galactic magnetic field. We estimate the size of these effects via numerical simulations using the CRPropa 3 package. The Jansson-Farrar and Terral-Ferrière models of the Galactic magnetic field are used to propagate particles from the edge of the Galaxy to an observer on Earth. We identify allowed directions and amplitudes of the dipole outside the Galaxy that are compatible with the measured features of the dipole on Earth for various mass composition scenarios at the 68% and 95% confidence level.
22 pages, 19 figures
References in corpus (10)
- Observation of a Large-scale Anisotropy in the Arrival Directions of Cosmic Rays above eV
- Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory: Measurements at Energies above 10^17.8 eV
- Features of the energy spectrum of cosmic rays above eV using the Pierre Auger Observatory
- Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum
- CRPropa 3.2 -- an advanced framework for high-energy particle propagation in extragalactic and galactic spaces
- Arrival Directions of Cosmic Rays above 32 EeV from Phase One of the Pierre Auger Observatory
- The Imprint of Large Scale Structure on the Ultra-High-Energy Cosmic Ray Sky
- Constraints from Faraday rotation on the magnetic field structure in the Galactic halo
- The Galactic Magnetic Field and Ultrahigh-Energy Cosmic Ray Deflections
- Galactic Magnetic Field Bias on Inferences from UHECR Data