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

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 extraga...

Full description

Saved in:
Bibliographic Details
Published inJournal of cosmology and astroparticle physics Vol. 2023; no. 12; pp. 16 - 37
Main Authors Bakalová, A., Vícha, J., Trávníček, P.
Format Journal Article
LanguageEnglish
Published Bristol IOP Publishing 01.12.2023
Subjects
Anisotropy
Astronomical models
Augers
Confidence intervals
Cosmic rays
Dipoles
galactic magnetic fields
Galaxies
High energy astronomy
Interstellar magnetic fields
Magnetic fields
ultra high energy cosmic rays
Online AccessGet full text

Cover

More Information
Summary: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 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.
ISSN:1475-7516
1475-7516
DOI:10.1088/1475-7516/2023/12/016