Sources in the direction of the Perseus cluster. Shown are the morphological categories (2) likely background ETG or source with unresolved substructure, (3) cluster or background LTG, (4) cluster or background galaxy with possibly weak substructure, (5) likely cluster or background edge-on disk galaxy, and (6) likely merging system in the background. For each source, we display the Subaru r-band image in the top panel and the (g − r)₀ color map in the bottom panel. The scale bar in each r-band image corresponds to a length of 10″. The color bar at the bottom of the figure indicates the (g − r)₀ values shown in the color maps.