CHEX-MATE: Density profile reconstruction in galaxy clusters

Abstract

We investigated the reconstruction of the intra-cluster medium radial density profiles in galaxy clusters, focusing on the impact of cluster morphology, dynamical state, and methodological choices, within the framework of the ̧hxmate project. Using a sample of 109 simulated galaxy clusters analysed along 40 independent lines of sight, we compared azimuthal mean and median techniques for deprojection. We find that azimuthal median-based density profiles recover the true gas density with negligible bias over the radial range 0.15-1.3 R_ 500 $. Mean based profiles are affected by the presence of substructures. While an accurate masking of clumps or substructures can reduce the bias to $< 5%$, the discrepancy increases substantially in disturbed systems or when substructures remain unresolved. The mean-to-median density ratio statistically traces projected gas inhomogeneities, although intrinsic scatter and projection effects limit its use for individual clusters. The complementary use of mean and median profiles therefore provides the most complete approach for large X-ray cluster samples.