Production and propagation of ultra-high energy photons using CRPropa 3

TL;DR

This paper introduces an enhanced photon production and propagation module within CRPropa 3, enabling detailed multi-messenger modeling of cosmic rays and photons across a broad energy spectrum, crucial for interpreting cosmic ray observations.

Contribution

The paper presents a new photon production and propagation code integrated into CRPropa 3, including additional channels for energies below 10^18 eV, advancing multi-messenger astrophysics tools.

Findings

Implementation of new photon production channels below 10^18 eV.

Demonstration of the code's application to cosmic ray source modeling.

Analysis of propagation effects and their significance in multi-messenger studies.

Abstract

In order to interpret cosmic ray observations, detailed modeling of propagation effects invoking all important messengers is necessary. We introduce a new photon production and propagation code as an inherent part of the CRPropa 3 software framework. By implementing additional photon production channels, which are important for energies below 10**18 eV, this code can be used for multi-messenger studies connecting the TeV and sub EeV energy regime and for interpreting models of ultra-high energy cosmic ray sources. We discuss the importance of the individual production channels and propagation effects and present example applications.