Distribution of galaxies in BGW superclusters in the sky plane. Red dots denote galaxies in the possible HDCs of each supercluster, and blue dots show galaxies in outskirts. Luminosity limits for HDCs are as follows: D8_HDC ≥ 15 in BGW A, D8_HDC ≥ 11 in BGW B, D8_HDC ≥ 14.5 in BGW C, and D8_HDC ≥ 16 in BGW D, where D8 is the value of the luminosity density (see text). Dark red circles show the turnaround regions in each HDC, and orange circles show the future collapse regions. Numbers with labels denote HDCs in each BGW supercluster.