2020/10/11 by Seonwoo Kim, Emanuele Contini, Hoseung Choi +5
Physics and Astronomy · #Astronomy and Astrophysical Research #Cluster (spacecraft) #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy formation and evolution #Halo #Scientific Research and Discoveries #Stellar mass #Virial mass #Virial theorem #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/abbfa6
10 pages, 8 figures, 2 tables. Accepted for publication in ApJ
arxiv created 2020/10/11 · openalex created_date 2020/10/15 · openalex publication_date 2020/12/01 · arxiv updated 2020/12/16 · openalex updated_date 2026/08/06
Abstract Mass segregation, a tendency for more massive galaxies to be distributed closer to the cluster center, is naturally expected from dynamical friction, but its presence is still controversial. Using deep optical observations of 14 Abell clusters (KYDISC) and a set of hydrodynamic simulations (YZiCS), we find in some cases a hint of mass segregation inside the virial radius. Segregation is visible more clearly when the massive galaxy fraction is used instead of mean stellar mass. The trend is more significant in the simulations than in the observations. To find out the mechanisms affecting mass segregation, we look into the evolution of individual simulated clusters. We find that the degree of mass segregation is different for different clusters: the trend is visible only for low-mass clusters. We compare the masses of galaxies and their dark halos at the time of infall and at the present epoch to quantify the amount of tidal stripping. We then conclude that satellites that get accreted at earlier epochs, or galaxies in more massive clusters, go through more tidal stripping. These combined effects result in a correlation between the host halo mass and the degree of stellar mass segregation.