Azimuthally averaged surface brightness profile (top) and corresponding surface density profile (bottom), demonstrating the effect of rounding off the disk wall (w> 0). The solid line shows the best-fit model with a wall shape of w = 0.30, as compared to a more vertical wall with w = 0.05 (dashed line). The dotted line indicates the “wall location” r, corresponding to the radial peak in intensity.