The Sunyaev-Zel'dovich temperature of the intracluster medium

Understand

The relativistic Sunyaev-Zel'dovich (SZ) effect offers a method, independent of X-ray, for measuring the temperature of the intracluster medium (ICM) in the hottest systems.

• Here, using N-body/hydrodynamic simulations of three galaxy clusters, we compare the two quantities for a non-radiative ICM, and for one that is subject both to radiative cooling and strong energy feedback from galaxies.
• Our study has yielded two interesting results.
• Firstly, in all cases, the SZ temperature is hotter than the X-ray temperature and is within ten per cent of the virial temperature of the cluster.