CosmoClusterPlasmas · The plasma physics of galaxy clusters in a cosmological context: connecting micro and macro scales

The plasma physics of galaxy clusters in a cosmological context: connecting micro and macro scales

Galaxy clusters are the largest gravitationally bound structures in the Universe and play a central role in modern cosmology. They are used to trace the growth of cosmic structure, to test theories of gravity, and to constrain the fundamental properties of dark matter and dark energy. A key component of galaxy clusters is the intracluster medium: a vast reservoir of extremely hot, diffuse plasma that emits X-rays and contains most of the normal (baryonic) matter in clusters. The physical state of this plasma encodes the formation history of clusters and the complex processes—such as turbulence, heating, cooling, and mergers—that shape them over billions of years. Until recently, direct measurements of gas motions inside galaxy clusters were beyond observational reach. This has now changed with the successful launch of the XRISM X-ray telescope, which is delivering high-precision measurements of intracluster gas velocities and turbulence. These observations are opening a new era in X-ray astronomy, allowing scientists to probe cluster dynamics and plasma processes under extreme conditions that cannot be reproduced in laboratories on Earth. However, exploiting this observational breakthrough requires equally advanced theoretical models. A major limitation of traditional cosmological simulations is the assumption that the intracluster medium behaves as a fully collisional fluid. In reality, the plasma in galaxy clusters is only weakly collisional, meaning that particle interactions, transport processes, and instabilities differ fundamentally from those in ordinary fluids. Neglecting these effects limits the accuracy of theoretical predictions and hampers the interpretation of high-quality X-ray data. The objective of this project was to overcome this limitation by developing and applying the first cosmological galaxy-cluster simulations that move beyond the standard collisional assumption. By incorporating the physics of weakly collisional plasmas into state-of-the-art numerical simulations, the project aimed to produce realistic predictions for turbulence, gas motions, and energy transport in galaxy clusters.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз