Iron Nuclei in Ultra-High Energy Cosmic Rays Near the Earth

TL;DR

This paper investigates how ultra-high energy cosmic iron nuclei propagate from extragalactic sources to Earth, focusing on their interactions, fragmentation, and how their observed energies can inform source distance constraints.

Contribution

It provides a detailed analysis of iron nuclei propagation, highlighting how their energy and composition can be used to infer source distances in extragalactic space.

Findings

Iron nuclei can reach Earth with energies above 10^19 eV.

Energy of iron nuclei depends on source distance due to interactions.

Iron nuclei observations can constrain source locations.

Abstract

The propagation of cosmic iron nuclei with energies above 10^19 eV from their sources to the Galaxy is discussed by assuming that cosmic rays at ultra-high energies are of extragalactic origin. In extragalactic space, cosmic nuclei interact with background emissions and inevitably fragment. An analysis is performed of the fraction of iron nuclei reaching the Earth and how its energy depends on the distance from cosmic ray sources. It is found that energies of iron nuclei can be used to determine restriction on the distances from their sources