Parameters V_c, Δx_c, Δy_c, and ΔV_sys corresponding to an assortment of tilted ring models whose χ² is within 2% of the absolute minimum value found. In the panels to the left the parameters for the v-mean minimization are shown, and in the panels to the right those for the shape minimization. The continuous line connects the parameters of the best fit tilted ring models used for deriving the rotation curve.