Quantifying properties of ICM inhomogeneities

We present a new method to identify and characterize the structure of the intraclus-ter medium (ICM) in simulated galaxy clusters. The method uses the median of gas properties, such as density and pressure, which we show to be very robust to the pres-ence of gas inhomogeneities. In particular, we show that the radial profiles of median gas properties in cosmological simulations of clusters are smooth and do not exhibit fluctuations at locations of massive clumps in contrast to mean and mode properties. Analysis of simulations shows that distribution of gas properties in a given radial shell can be well described by a log-normal PDF and a tail. The former corresponds to a nearly hydrostatic bulk component, accounting for ∼ 99 per cent of the volume, while the tail corresponds to high density inhomogeneities. The clumps can thus be easily identified with the volume elements corresponding to the tail of the distribution. We show that this results in a simple and robust separation of the diffuse and clumpy components of the ICM. The full width half maximum of the density distribution in simulated clusters is a growing function of radius and varies from ∼ 0.15 dex in cluster