First results on the cluster galaxy population from the Subaru Hyper
  Suprime-Cam survey. II. Faint end color-magnitude diagrams and radial
  profiles of red and blue galaxies at $0.1<z<1.1$
  We present a statistical study of the redshift evolution of the cluster
galaxy population over a wide redshift range from 0.1 to 1.1, using $\sim 1900$
optically-selected CAMIRA clusters from $\sim 232$~deg$^2$ of the Hyper
Suprime-Cam (HSC) Wide S16A data. Our stacking technique with a statistical
background subtraction reveals color-magnitude diagrams of red-sequence and
blue cluster galaxies down to faint magnitudes of $m_z\sim 24$. We find that
the linear relation of red-sequence galaxies in the color-magnitude diagram
extends down to the faintest magnitudes we explore with a small intrinsic
scatter $\sigma_{\rm int}(g-r)<0.1$. The scatter does not evolve significantly
with redshift. The stacked color-magnitude diagrams are used to define red and
blue galaxies in clusters for studying their radial number density profiles
without resorting to photometric redshifts of individual galaxies. We find that
red galaxies are significantly more concentrated toward cluster centers and
blue galaxies dominate the outskirt of clusters. We explore the fraction of red
galaxies in clusters as a function of redshift, and find that the red fraction
decreases with increasing distances from cluster centers. The red fraction
exhibits a moderate decrease with increasing redshift. The radial number
density profiles of cluster member galaxies are also used to infer the location
of the steepest slope in the three dimensional galaxy density profiles. For a
fixed threshold in richness, we find little redshift evolution in this
location.
