Light cone centred on z_clus = 0.4828 and extending to ±1δ_cl in redshift. In right ascension, 1° is covered. The vertical line is located at the cluster redshift, z_cl = 0.4828. The grey points are for the galaxies with a photometric redshift. Galaxies with spectroscopic redshifts are in black. Our sample is in green, and lower μ_H2 (see Sect. 4.1) galaxies are outlined in pink. Distances are expressed relative to the brightest cluster galaxy (BCG).