Lens modeling of the ¹²CO(9 − 8) spectral channels. The velocity ranges covered by each channel are marked in the right-hand panels. From left to right: observed image (with the synthesized beam shown in the lower left corner) and critical curve (red line); reconstructed model image convolved with the PSF; residuals, reconstructed model image at full angular resolution; and, separated and with a different angular scale, reconstructed source-plane images and caustic curve. The cross shows the central coordinate RA 13:16:11.52 and Dec +28:12:17.7 (J2000).