부산대학교 도서관

Concentration is one of the key dark matter halo properties that could drive the scatter in the stellar-to-halo mass relation of massive clusters. We derive robust photometric stellar masses for a sample of brightest central galaxies (BCGs) in SDSS redmapper clusters at 0.17 < z < 0.3, and split the clusters into two equal-halo mass subsamples by their BCG stellar mass |$M_*^{\mathrm{BCG}}$|⁠. The weak lensing profiles ΔΣ of the two cluster subsamples exhibit different slopes on scales below |$1\, h^{-1}\, {\mathrm{Mpc}}$|⁠. To interpret such discrepancy, we perform a comprehensive Bayesian modelling of the two ΔΣ profiles by including different levels of miscentring effects between the two subsamples as informed by X-ray observations. We find that the two subsamples have the same average halo mass of |$1.74\times 10^{14}\, h^{-1}\, \mathrm{M}_{\odot }$|⁠ , but the concentration of the low- |$M_*^{\mathrm{BCG}}$| clusters is |$5.87_{-0.60}^{+0.77}$|⁠ , ∼1.5σ smaller than that of their high- |$M_*^{\mathrm{BCG}}$| counterparts (⁠|$6.95_{-0.66}^{+0.78}$|⁠). Furthermore, both cluster weak lensing and cluster-galaxy cross-correlations indicate that the large-scale bias of the low- |$M_*^{\mathrm{BCG}}$|⁠ , low-concentration clusters are |${\sim}10{{\ \rm per\ cent}}$| higher than that of the high- |$M_*^{\mathrm{BCG}}$|⁠ , high-concentration systems, hence possible evidence of the cluster assembly bias effect. Our results reveal a remarkable physical connection between the stellar mass within |$20{-}30\, h^{-1}\, {\mathrm{kpc}}$|⁠ , the dark matter mass within |${\sim}200\, h^{-1}\, {\mathrm{kpc}}$|⁠ , and the cosmic overdensity on scales above |$10\, h^{-1}\, {\mathrm{Mpc}}$|⁠ , enabling a key observational test of theories of co-evolution between massive clusters and their central galaxies. [ABSTRACT FROM AUTHOR]