Spatial and Kinematic Distributions of Transition Populations in
  Intermediate Redshift Galaxy Clusters
  We analyze the spatial and velocity distributions of confirmed members in
five massive clusters of galaxies at intermediate redshift (0.5 < z < 0.9) to
investigate the physical processes driving galaxy evolution. Based on spectral
classifications derived from broad- and narrow-band photometry, we define four
distinct galaxy populations representing different evolutionary stages: red
sequence (RS) galaxies, blue cloud (BC) galaxies, green valley (GV) galaxies,
and luminous compact blue galaxies (LCBGs). For each galaxy class, we derive
the projected spatial and velocity distribution and characterize the degree of
subclustering. We find that RS, BC, and GV galaxies in these clusters have
similar velocity distributions, but that BC and GV galaxies tend to avoid the
core of the two z~0.55 clusters. GV galaxies exhibit subclustering properties
similar to RS galaxies, but their radial velocity distribution is significantly
platykurtic compared to the RS galaxies. The absence of GV galaxies in the
cluster cores may explain their somewhat prolonged star-formation history. The
LCBGs appear to have recently fallen into the cluster based on their larger
velocity dispersion, absence from the cores of the clusters, and different
radial velocity distribution than the RS galaxies. Both LCBG and BC galaxies
show a high degree of subclustering on the smallest scales, leading us to
conclude that star formation is likely triggered by galaxy-galaxy interactions
during infall into the cluster.
