First results on the cluster galaxy population from the Subaru Hyper
  Suprime-Cam survey. III. Brightest cluster galaxies, stellar mass
  distribution, and active galaxies
  The unprecedented depth and area surveyed by the Subaru Strategic Program
with the Hyper Suprime-Cam (HSC-SSP) have enabled us to construct and publish
the largest distant cluster sample out to $z\sim 1$ to date. In this
exploratory study of cluster galaxy evolution from $z=1$ to $z=0.3$, we
investigate the stellar mass assembly history of brightest cluster galaxies
(BCGs), evolution of stellar mass and luminosity distributions, stellar mass
surface density profile, as well as the population of radio galaxies. Our
analysis is the first high redshift application of the top N richest cluster
selection, which is shown to allow us to trace the cluster galaxy evolution
faithfully. Over the 230 deg$^2$ area of the current HSC-SSP footprint,
selecting the top 100 clusters in each of the 4 redshift bins allows us to
observe the buildup of galaxy population in descendants of clusters whose
$z\approx 1$ mass is about $2\times 10^{14}\,M_\odot$. Our stellar mass is
derived from a machine-learning algorithm, which is found to be unbiased and
accurate with respect to the COSMOS data. We find very mild stellar mass growth
in BCGs (about 35% between $z=1$ and 0.3), and no evidence for evolution in
both the total stellar mass-cluster mass correlation and the shape of the
stellar mass surface density profile. We also present the first measurement of
the radio luminosity distribution in clusters out to $z\sim 1$, and show hints
of changes in the dominant accretion mode powering the cluster radio galaxies
at $z\sim 0.8$.
