Physics of cosmic plasmas from high angular resolution X-ray imaging of galaxy clusters

TL;DR

High-resolution X-ray imaging of galaxy clusters is crucial for studying plasma properties that are otherwise inaccessible, aiding our understanding of astrophysical phenomena and the universe's large-scale structure.

Contribution

This paper advocates for the development of arcsecond-resolution, high collecting area X-ray imagers like AXIS and Lynx to advance plasma studies in galaxy clusters.

Findings

High-resolution imaging can probe plasma properties inaccessible by other means.

Current instruments like Chandra have limited capabilities for these studies.

Future missions will significantly enhance our understanding of cluster plasmas.

Abstract

Galaxy clusters are massive dark matter-dominated systems filled with X-ray emitting, optically thin plasma. Their large size and relative simplicity (at least as astrophysical objects go) make them a unique laboratory to measure some of the interesting plasma properties that are inaccessible by other means but fundamentally important for understanding and modeling many astrophysical phenomena -- from solar flares to black hole accretion to galaxy formation and the emergence of the cosmological Large Scale Structure. While every cluster astrophysicist is eagerly anticipating the direct gas velocity measurements from the forthcoming microcalorimeters onboard XRISM, Athena and future missions such as Lynx, a number of those plasma properties can best be probed by high-resolution X-ray imaging of galaxy clusters. Chandra has obtained some trailblazing results, but only grazed the surface of such studies. In this white paper, we discuss why we need arcsecond-resolution, high collecting area, low relative background X-ray imagers (with modest spectral resolution), such as the proposed AXIS and the imaging detector of Lynx.