On the non-thermal energy content of cosmic structures

TL;DR

This paper investigates the distribution and impact of non-thermal energy in galaxy clusters using cosmological simulations, highlighting its significance for future high-precision cosmology and understanding cosmic particle acceleration.

Contribution

It provides new insights into the spatial distribution and dominant components of non-thermal energy in galaxy clusters through advanced simulations.

Findings

Non-thermal energy increases in cluster outskirts.

Turbulent motions dominate the non-thermal energy budget.

Understanding non-thermal energy aids high-precision cosmology.

Abstract

1) Background: the budget of non-thermal energy in galaxy clusters is not well constrained, owing to the observational and theoretical difficulties in studying these diluted plasmas on large scales. 2) Method: we use recent cosmological simulations with complex physics in order to connect the emergence of non-thermal energy to the underlying evolution of gas and dark matter. 3) Results: the impact of non-thermal energy (e.g. cosmic rays, magnetic fields and turbulent motions) is found to increase in the outer region of galaxy clusters. Within numerical and theoretical uncertainties, turbulent motions dominate the budget of non-thermal energy in most of the cosmic volume. 4) Conclusion: assessing the distribution non-thermal energy in galaxy clusters is crucial to perform high-precision cosmology in the future. Constraining the level of non-thermal energy in cluster outskirts will improve our understanding of the acceleration of relativistic particles by cosmic shocks and of the origin of extragalactic magnetic fields.