Signatures of Magnetized Large Scale Structure in Ultra-High Energy Cosmic Rays

TL;DR

This paper explores how magnetic fields and structured sources influence ultra-high energy cosmic rays, suggesting current data slightly favor structured sources with micro Gauss magnetic fields, and predicts a GZK cutoff.

Contribution

It compares structured versus uniform source distributions with magnetic fields from cosmological simulations, highlighting their effects on cosmic ray observables.

Findings

Current data marginally favor structured sources with micro Gauss magnetic fields.

A pronounced GZK cutoff is predicted in the structured universe scenario.

Future experiments could detect micro Gauss magnetic fields via auto-correlation functions.

Abstract

We investigate the impact of a structured universe in the multi-pole moments, auto-correlation function, and cluster statistics of cosmic rays above 10^19 eV. We compare structured and uniform source distributions with and without magnetic fields obtained from a cosmological simulation. We find that current data marginally favor structured source distributions and magnetic fields reaching a few micro Gauss in galaxy clusters but below 0.1 micro Gauss in our local extragalactic neighborhood. A pronounced GZK cutoff is also predicted in this scenario. Future experiments will make the degree scale auto-correlation function a sensitive probe of micro Gauss fields surrounding the sources.