The 15″ × 15″ (~125 kpc × 125 kpc at z ~ 2) immediate surroundings of MRC 0156-252 at optical and near-infrared wavelengths: B-band pre-imaging (left panel; this work) and Y (middle) and K_s (right) bands (G10). North is up; East is to the left. The two FORS2 slits dedicated to observing the different radio galaxy companions are shown in cyan (positions angles of − 55° and − 10° for the first and second mask, respectively). Radio contours from 4.7 GHz imaging by the VLA are overplotted in green (Carilli et al. 1997). The radio galaxy and companions are designated by “A”, “B”, “C”, and “D” for consistency with the notation of Pentericci et al. (2001) and G10. We introduce “A′” for the closest source to A revealed by the FORS2 B-band image and “E” for a suspected faint companion at the edge of the SW radio lobe.