RGB image using the F090W, F277W, and F444W filters, with overlaid points indicating the positions of spectroscopically confirmed galaxies (squares, solid line) and photometric candidates (circles). The large dashed squares indicate the most clustered core regions. The left square includes four PRGs, while the right square contains seven PRGs, these objects compose the ‘core’ regions (as defined in Section 6). Two of the 23 galaxies are not shown in this figure as they lie at a larger separation than the chosen field of view. The axis ticks are intended to indicate the approximate distances between galaxies after correcting for magnification (assuming a constant μ = 1.9; while this does vary across the RGB image, this effect is minimal).