GALPROP cosmic-ray propagation code: recent results and updates

TL;DR

GALPROP is a comprehensive cosmic-ray propagation code that integrates diverse observational data to improve understanding of cosmic-ray behavior and interstellar medium interactions, with recent updates enhancing its 3D modeling capabilities.

Contribution

This paper reviews recent applications and updates of GALPROP, emphasizing the transition to a full 3D model and its implications for cosmic-ray studies.

Findings

Incorporation of 3D interstellar medium models improves accuracy.

Comparison of different propagation models highlights key effects.

Recent updates enable better interpretation of cosmic-ray data.

Abstract

Information on cosmic-ray (CR) composition comes from direct CR measurements while their distribution in the Galaxy is evaluated from observations of their associated diffuse emission in the range from radio to gamma rays. Even though the main interaction processes are identified, more and more precise observations provide an opportunity to study more subtle effects and pose a challenge to the propagation models. GALPROP is a sophisticated CR propagation code that is being developed for about 20 years. It provides a unified framework for interpretations of data from many different types of experiments. It is used for a description of direct CR measurements and associated interstellar emissions (radio to gamma rays), thereby providing important information about CR injection and propagation in the interstellar medium. By accounting for all relevant observables at a time, the GALPROP code brings together theoretical predictions, interpretation of the most recent observations, and helps to reveal the signatures of new phenomena. In this paper we review latest applications of GALPROP and address ongoing and near future improvements. We are discussing effects of different propagation models, and of the transition from cylindrically symmetrical models to a proper 3D description of the components of the interstellar medium and the source distribution.