Scaling relations of X-ray Luminous Clusters in the Hyper Suprime-Cam Subaru Strategic Program Field

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 cluster catalogue in the Hyper Suprime-Cam Subaru Strategic Program 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 𝑌 X -𝑀 tot and 𝑀 gas -𝑀 tot relations agree with self-similarity. In terms of morphology, relaxed clusters show a flatter relation in 𝐿 X,ce -𝑀 tot , 𝐿 X,bol -𝑀 tot , 𝐿 X,ce -𝑇, 𝐿 bol,ce -𝑇, 𝑀 gas -𝑀 tot and 𝑌 X -𝑀 tot . The 𝐿 bol,ce -𝑀 tot , 𝐿 X,ce -𝑀 tot 𝐿 bol,ce -𝑇 and 𝐿 X,ce -𝑇 relations show a slope ∼3𝜎 steeper. The residuals in the 𝑀 gas -𝑀 tot and 𝑇-𝑀 tot relations and the intrinsic covariance between 𝑀 gas and 𝑇 show hints of positive correlation, casting doubt on whether the 𝑌 X parameter is a truly low scatter mass proxy. The 𝑀 gas -𝑀 tot and 𝑇-𝑀 tot plots color-coded with the offset of the 𝐿 X,ce -𝑀 tot relation show these two relations to be brightness dependent but not the 𝐿 X,ce -𝑇 relation, suggesting relations involving 𝑀 tot are biased due to sample selection based on luminosity. Following the work which studied an optical sample and combining our result with literature studies, we find the 𝑀 tot derived not using mass proxies deviate from 𝐿 X ∝ 𝑀 2 gas 𝑀 −1 tot and 𝑀 tot based on hydrostatic equilibrium are more massive than what is expected by their relation using caustic masses. This indicates mass bias plays an important role in scaling relations.