Optimally extracted map of the LAB, obtained using the CubEx software on the PSF and continuum subtracted MUSE datacube, and by collapsing along the wavelength axis the datacube voxels inside the 3D segmentation map. The spatial projection of the 3D mask is indicated by the thick contour that corresponds to an SB of about 1 × 10^-18 erg s^-1 cm^-2 arcsec^-2 and an S/N of 2.3. The thin contours indicate the propagated S/N in the images, the outermost one corresponding to S/N = 2 and the other ones to S/Ns increasing by steps of 6 units (see B16 for a detailed explanation). The QSO position is shown by the black dot. Note the long tail extending southward of the QSO; this was unknown to date.