On-sky distribution of the galaxies listed in Table 3 in equatorial coordinates relative to the position of NGC 253 (black cross). The galaxies are colour-coded according to their line-of-sight velocity component relative to the NGC 253 velocity. Galaxies without velocity measurements are plotted in black. Galaxies (potentially) within 600 kpc of NGC 253 are marked with yellow boxes. The dashed black line indicates the on-sky orientation of the flattening of these objects.