Comparison between the radial profile of the polarised intensity obtained from models and from the observations in V (black line) for the different octants. Octant one is limited by the north and north-east directions and the numeration follows clock-wise. The grey-filled region shows the three-σ errors from combining the uncertainty given by the ESO pipeline with that from choosing the central pixel. The different octants are identified by number in each panel (see Sect. 2.2.2). We show the best fit models for: a thin halo (pink line), n = 5 (cyan line), n = 4 (red line), n = 3 (green line), and n = 2 (blue line). The filled regions around the model lines show variation with direction introduced by the convolution with the PSF.