Comparison of the nonparametric properties of the line profiles (denoted by different colors and with 1σ uncertainties). Panel a: line widths (circles, triangles, and squares represent W₂₅, W₅₀, and W₇₅, respectively). Panel b: asymmetry index (A.I.). Panel c: kurtosis index (K.I.). In the panels, the gray lines correspond to equivalent measurements on the model line profiles for the separate (dotted) and combined (solid) fitting results.