Core of MACS J1206. Red circles represent the multiple images (see B19 for details). The locations of the three mass clumps proposed by B19 are shown by cyan ellipses, whose size represents the 1σ error bar on the position. Yellow boxes represent the prior on the position of the mass clumps included in the different mass model. North is up, east is left. The size of the field is 166″ × 110″.