The Dependence of Cluster Galaxy Properties on the Central Entropy of Their Host Cluster

Abstract

Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractWe present a study of the connection between brightest cluster galaxies (BCGs) and their host galaxy clusters. Using galaxy clusters at < < z 0.1 0.3 from the Hectospec Cluster Survey (HeCS) with X-ray information from the Archive of Chandra Cluster Entropy Profile Tables (ACCEPT), we confirm that BCGs in low central entropy clusters are well aligned with the X-ray center. Additionally, the magnitude difference between BCG and the second brightest galaxy also correlates with the central entropy of the intracluster medium. From the red-sequence (RS) galaxies, we cannot find significant dependence of RS color scatter and stellar population on the central entropy of the intracluster medium of their host cluster. However, BCGs in low-entropy clusters are systematically less massive than those in high-entropy clusters, although this is dependent on the method used to derive the stellar mass of BCGs. In contrast, the stellar velocity dispersion of BCGs shows no dependence on BCG activity and cluster central entropy. This implies that the potential of the BCG is established earlier and the activity leading to optical emission lines is dictated by the properties of the intracluster medium in the cluster core.

Coevolution of Brightest Cluster Galaxies and Their Host Clusters in IllustrisTNG

“…Sohn et al (2020) show that σ *,BCG /σ cl decreases as a function of σ cl , based on the HeCS-omnibus sample, which compiles dense spectroscopy of 227 clusters. A similar relation appears in other cluster samples (e.g., Kim et al 2017;Sohn et al 2021). The decreasing σ *,BCG /σ cl ratio at higher σ cl indicates that the mass fraction associated with the BCG halo decreases in higher-mass clusters.…”

Co-evolution of the Brightest Cluster Galaxies and their Host Clusters in IllustrisTNG

“…Sohn et al (2020) show that σ * ,BCG /σ cl decreases as a function of σ cl based on the HeCS-omnibus sample that compiles dense spectroscopy of 227 clusters. A similar relation appears in other cluster samples (e.g., Kim et al 2017;Sohn et al 2021). The decreasing σ * ,BCG /σ cl ratio at higher σ cl indicates that the mass fraction associated with the BCG halo decreases in higher mass clusters.…”

Spatial Distribution of Dark Matter in and Around Galaxy Clusters Traced by Galaxies, Gas, and Intracluster Stars in a Simulated Universe

“…Unlikely due to the insignificant difference in the σ δPA between the virialized and unvirialized subsamples for all components at all radii (see Figure 14), the σ offset at R = 2R vir shows a significant difference (see Figure 15), where the centroid of each component from the unvirialized subsample is less aligned to that of dark matter. This result is consistent with the observations showing that X-ray peak and the BCG tend to be separated more for non-cool-core clusters, which are believed to be associated with recent major merging events and thus tend to be more unvirialized (Katayama et al 2003;Sanderson et al 2009;Hudson et al 2010;Hoffer et al 2012;Kim et al 2017). At R = 0.5 and 1R vir , on the other hand, the σ offset between the two subsamples does not show a significant difference.…”