Ultrahigh Energy Nuclei in the Galactic Magnetic Field

TL;DR

This paper simulates the propagation of ultrahigh energy heavy nuclei through the Galactic magnetic field to understand their deflections and implications for source identification.

Contribution

It provides detailed simulations of heavy nuclei in recent Galactic magnetic field models, highlighting general deflection features relevant for cosmic ray source reconstruction.

Findings

Heavy nuclei are significantly deflected by the Galactic magnetic field.

General flux magnification and demagnification patterns are identified.

Examples of source images from nearby galaxy clusters are presented.

Abstract

Observations are consistent with a significant fraction of heavy nuclei in the cosmic ray flux above a few times 10^19 eV. Such nuclei can be deflected considerably in the Galactic magnetic field, with important implications for the search of their sources. We perform detailed simulations of heavy nuclei propagation within recent Galactic magnetic field models. While such models are not yet sufficiently constrained to predict deflection maps in detail, we find general features of the distribution of (de-) magnified flux from sources. Since in most theoretical models sources of heavy nuclei are located in the local large scale structure of galaxies, we show examples of images of several nearby galaxy clusters and of the supergalactic plane. Such general features may be useful to develop efficient methods for source reconstruction from observed ultrahigh energy cosmic ray arrival directions.