Modification of the dipole in arrival directions of ultra-high-energy cosmic rays due to the Galactic magnetic field

0581804 - FZÚ 2024 RIV US eng J - Journal Article
Bakalová, Alena - Vícha, Jakub - Trávníček, Petr
Modification of the dipole in arrival directions of ultra-high-energy cosmic rays due to the Galactic magnetic field.
Journal of Cosmology and Astroparticle Physics. Roč. 2023, č. 12 (2023), č. článku 016. ISSN 1475-7516. E-ISSN 1475-7516
R&D Projects: GA MŠMT LTT18004; GA MŠMT EF16_013/0001402; GA MŠMT(CZ) EF18_046/0016010
Research Infrastructure: AUGER-CZ III - 90232
Institutional support: RVO:68378271
Keywords : ultra high energy cosmic rays * galactic magnetic fields
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.3, year: 2022
Method of publishing: Open access

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 within the Galaxy. 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.
Permanent Link: https://hdl.handle.net/11104/0349957