Galactic Centre as an efficient source of cosmic rays

TL;DR

This paper investigates the Galactic Centre's role as a significant source of cosmic rays by modeling cosmic ray diffusion and comparing results with observed spectra, highlighting its contribution to cosmic ray flux and composition at Earth.

Contribution

It introduces a diffusion/re-acceleration model using GALPROP to analyze cosmic ray origins and gamma-ray emissions from the Galactic Centre, considering various interstellar gas interactions.

Findings

Galactic Centre significantly contributes to cosmic ray flux at Earth.

Model matches observed gamma-ray spectra from the Galactic Centre.

Nuclei interactions influence cosmic ray composition and spectrum.

Abstract

After the discovery of Fermi Bubbles and the excess of gamma-ray emission, the Galactic Centre has received increasing attention with the aim to understand its role in the origin and acceleration of primary cosmic rays (CRs). Based on a diffusion/re-acceleration model, we use the GALPROP software to solve the diffusion equation for the cosmic rays and compare the results with the CRs spectrum, motivated by relationship between several energetic sources at the Galactic Centre and the generated diffuse GeV-TeV gamma-rays. We calculate the cosmic ray distribution, gamma-ray flux from Galactic Centre and explore its contribution on the spectrum and chemical composition of cosmic rays observed at Earth. We also discuss the effects of nuclei interactions with different interstellar gas models.