# Astro2020 Science White Paper: A Unification of the Micro and Macro Physics in the Intracluster Medium of Nearby Clusters

## TL;DR

This white paper discusses the importance of understanding the microphysical properties of intracluster plasma in galaxy clusters to improve cosmological models and simulations, highlighting recent progress and future prospects.

## Contribution

It emphasizes the need to measure microphysical properties of intracluster plasma and reviews recent advances and future X-ray missions for this purpose.

## Key findings

- High-resolution X-ray imaging has advanced understanding of plasma properties.
- Future X-ray calorimeter missions will enable direct measurements of transport coefficients.
- Current simulations often assume inviscid plasma, which may oversimplify real physics.

## Abstract

Clusters of galaxies are the most massive virialized structures in the Universe. The microphysical properties of the intracluster plasma can affect dynamical processes over an enormous range: from the feedback of active galactic nuclei to shock acceleration in merging clusters. All the major cosmological simulations assume the astrophysical plasma to be inviscid. It is critical to measure microphysical properties of the intracluster plasma to truly understand the physical processes that drive the cosmic evolution. Tremendous progress has been made by comparing high spatial resolution X-ray images to (magneto-)hydrodynamic simulations. Future X-ray missions with calorimeters promise a direct measurement of transport coefficients and gas motions, providing a more realistic benchmark for cosmological simulations.