Scaling relations of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program field

Abstract

ABSTRACT We present the XMM–Newton X-ray analysis of 19 X-ray luminous galaxy clusters of low- to mid-redshift (<0.4) selected from the MCXC (Meta-Catalog of X-Ray Detected Clusters of Galaxies) cluster catalogue in the Hyper Suprime-Cam Subaru Strategic Programme field. We derive the hydrostatic equilibrium mass and study scaling relations using (i) the whole sample, (ii) only relaxed clusters, and (iii) only disturbed clusters. When considering the whole sample, the YX–Mtot and Mgas–Mtot relations agree with self-similarity. In terms of morphology, relaxed clusters show a flatter relation in LX,ce–Mtot, LX,bol–Mtot, LX,ce–T, Lbol,ce–T, Mgas–Mtot, and YX–Mtot. The Lbol,ce–Mtot, LX,ce–Mtot Lbol,ce–T, and LX,ce–T relations show a slope ∼3σ steeper. The residuals in the Mgas–Mtot and T–Mtot relations and the intrinsic covariance between Mgas and T show hints of positive correlation, casting doubt on whether the YX parameter is a truly low-scatter mass proxy. The Mgas–Mtot and T–Mtot plots colour coded with the offset of the LX,ce–Mtot relation show these two relations to be brightness dependent but not the LX,ce–T relation, suggesting that relations involving Mtot are biased due to sample selection based on luminosity. Following the work that studied an optical sample and combining our result with literature studies, we find that Mtot derived not using mass proxies deviates from LX ∝ $M_{\rm gas}^{2}M_{\rm tot}^{-1}$ and Mtot based on hydrostatic equilibrium is more massive than what is expected by their relation using caustic masses. This indicates that mass bias plays an important role in scaling relations.