UHECR propagation in the Galactic Magnetic Field

TL;DR

This paper presents extensive simulations of ultra-high energy cosmic ray propagation through the Galactic magnetic field, revealing how different models affect deflection patterns and the exposure of cosmic ray experiments to extragalactic sources.

Contribution

It provides a comparative analysis of various Galactic magnetic field models and their impact on cosmic ray deflections and source correlations.

Findings

Different GMF models produce distinct deflection patterns.

Galactic magnetic lensing alters the exposure of UHECR experiments.

Correlation analysis with AGN shows the importance of magnetic field effects.

Abstract

Extensive simulations of the ultra-high energy cosmic ray (UHECR) propagation in the Galactic magnetic field (GMF) have been performed, and the results are presented. The use of different available models of the large-scale GMF and/or primary particle assumptions leads to distinctly different deflection patterns of the highest energy cosmic rays (CR). The lensing effects of the Galactic field modify the exposure of an UHECR experiment to the extragalactic sky. To quantify these effects for the Pierre Auger experiment, we performed a correlation analysis of the simulated cosmic ray event samples, backtracked from the Earth to the Galactic border, with the active galactic nuclei (AGN) from the 12th edition of the V\'eron-Cetty and V\'eron catalogue. Further forward-tracking studies under plausible UHECR sources scenarios are needed to allow for direct comparison with the observed correlation between the nearby AGN and the highest energy Auger events.