Results of the emcee MCMC optimization using a single radial power law for the surface density. The panels show one- and two-dimensional projections of the posterior probability functions of the free model parameters. The panels along the diagonal show the marginalized distribution of each of the parameters as histograms; the other panels show the marginalized two-dimensional distributions for each set of two parameters. Contours (barely visible in the tightly constrained probability distributions) and associated greyscale show 0.5, 1, 1.5 and 2σ levels. Best-fit values and error estimates are listed above the panels along the diagonal.