Left panel: example of one profile parameter, such as the right integrated intensity obtained for all models. The horizontal lines on the diagram represent the values of the parameter for the observed profiles − dotted line for A brightening, dashed line for B, dashed dotted line C, dashed-dotted-dotted-dotted for D and long dashed line for E. Right panel: the square root of the mean-square intensity difference between synthetic and observed profiles: one example of the A brightening. The best model for A is N = 120.