A new 3D transport and radiation code for galactic cosmic rays

TL;DR

This paper introduces a new 3D transport and radiation code for simulating galactic cosmic ray propagation, addressing the limitations of previous models by incorporating inhomogeneous diffusion and small-scale structures.

Contribution

The paper presents a novel 3D cosmic ray transport code that improves upon existing models by handling inhomogeneous diffusion and small-scale galactic structures.

Findings

Transition from 2D to 3D simulations demonstrated

Sub-kpc scale simulations reveal small-scale structure effects

New code capabilities enable detailed cosmic ray propagation studies

Abstract

We show the necessity for a new approach towards comprehensive and consistent simulations of the propagation of galactic cosmic rays. Our developments are optimised for addressing the spatially 3-dimensional inhomogeneous diffusion problem and utilise contemporary numerical methods. We aim to address the transport problem in a full 3-dimensional environment. For that, we test the transition from 2D to 3D simulation results within an existing propagation code. We present sub-kpc scale simulations that allow the investigation of small- scale structures regarding different model conditions such as variety regarding non-axisymmetric cosmic ray source distributions. These results are discussed critically and motivate our development of a new transport code for galactic cosmic rays. The capabilities of this code are outlined.