The scatter in the radial profiles of X-ray luminous galaxy clusters as diagnostic of the thermodynamical state of the ICM

TL;DR

This study analyzes the azimuthal scatter in X-ray galaxy clusters' radial profiles using simulations, revealing typical variability levels and their dependence on cluster state, aiding interpretation of observational data.

Contribution

It provides a detailed comparison of simulated azimuthal scatter in galaxy clusters with observations, highlighting its diagnostic potential for the ICM's thermodynamical state.

Findings

Azimuthal scatter is about 10% for gas density, temperature, and entropy inside R200.

Scatter increases to about 25% for X-ray luminosity within the same volume.

Perturbed systems exhibit 20-40% higher scatter levels.

Abstract

We study the azimuthal scatter in the radial profiles of X-ray luminous galaxy clusters, with two sets of high-resolution cosmological re-simulations obtained with the codes ENZO and GADGET2. The average gas profiles are computed for different angular sectors of the cluster projected volume, and compared with the mean cluster profiles at each radius from the center. We report that in general the level of azimuthal scatter is found to be about 10 per cent for gas density, temperature and entropy inside R200, and about 25 per cent for X-ray luminosity for the same volume. These values generally doubles going to 2 R200 from the cluster center, and are generally found to be higher (by about 20-40 percent) in the case of perturbed systems. A comparison with results from recent SUZAKU observations is discussed, showing the possibility to simply interpret the large azimuthal scatter of observables in light of our simulated results.