Probability density distributions of the parameters of the PIEMD+rc (in blue) and SPEMD (in red) models. The marginalized 1D histograms of each parameter are shown along the diagonal, while the other panels show the joint 2D probability distributions of the two parameters reported on the horizontal and vertical axes. The parameters plotted are those introduced in Sect. 4.1. The vertical dashed lines in the 1D histograms represent the 16th, 50th, and 84th percentiles, while the solid lines in the 2D distributions represent the 0.68 and 0.95 contour levels.