Likelihood distribution resulting from our simple Galaxy model when we leave the halo concentration c (and therefore also V_LSR) as a free parameter (blue area) for an NFW profile as halo model (left panel) and an adiabatically contracted NFW profile (right panel). The red contours arise when we add the constraints on c from cosmological simulations: the relation of the mean c for a given halo mass found by Macciò et al. (2008) is represented by the thick dashed orange line. The orange area illustrates the spread around the mean c values found in the simulations. The different shades in the blue and orange colored areas mark locations where the probability dropped to 10%, 1% of the maximum value as do the black contour lines for the combined likelihood distribution. Dotted gray lines connect locations with constant circular speed at the solar radius.