Location of L15 detected galaxies. The circles and the triangles indicate galaxies with and without a spectroscopic redshift, respectively. The red and blue symbols indicate those with log L8/LIR <−0.75 and log L8/LIR >−0.75, respectively. This boundary is 1σ smaller than that of the main-sequence galaxies determined in Elbaz et al. (2011). The grey crosses indicate the member galaxies without L15 detection. The black dotted lines indicate the 1 and 2 Mpc radii from the cluster centre. The green solid lines indicate the three clumps in Demarco et al. (2005).