Joint PDF for the three-parameter model with a Gaussian component and a uniform contamination population. The marginalized PDF for the mean velocity ﹩\langle {v}_{r}\rangle ﹩, the fraction of contaminants η, and the velocity dispersion σ_int are also shown. Despite the contamination component, the PDF on the velocity dispersion remains similar to that of Figure 1, with ﹩{\sigma }_{\mathrm{int}}={9.2}_{-3.6}^{+4.8}\,\mathrm{km}\,{{\rm{s}}}^{-1}﹩.