Simultaneous fitting of the fundamental mode and overtone PL relation for the M 51 Cepheid sample. For this run, an offset of 0.75 magnitudes was assumed between the two modes. The red line corresponds to the MAP estimate. The light grey points denote the data points that were rejected by the outlier detection method, and the solid points show the points that were used to fit the relation. As before, the displayed distance uncertainty includes the aforementioned systematic terms.