Maximum a posteriori lens models for the band 7 data. First column: Lens model. Crosses show lens and sub-halo positions; critical curves are in black. Second column: Difference in convergence relative to the PL model. Contours of the sky model are in grey. Third column: Difference in magnification relative to the PL model; contours of the sky model in black. Fourth column: Image of the residuals (data–model) normalised by the RMS noise (σ), with the mask shown by the dashed outline. Last column: Reconstructed source with Gouraud interpolation and caustics in black. The locations of I16 and H16 purported sub-haloes are shown with a triangle and a circle, respectively.