Contour plots describing the data/model agreement in the computation of the distance between the GRB and component II. The four plots display the contours in the plane of Doppler parameter and GRB/absorber distance for different initial Fe ii column densities. Black, violet, cyan and green contours enclose the 68%, 90%, 95% and 99% confidence regions, respectively. The bottom right panel is empty as at the corresponding density no combination of Doppler parameter and distance falls inside the 99% confidence surface.