Flare intensity as a function of log(L_X), where observed data from BeXRBs are plotted with magenta colors. The best-fit line (black) and the 68–99% prediction bands are plotted with gray shade, while model parameters are given in the legend. For the modeled excess variance, we also plot an indicative spread with a maroon color, for easier comparison with the data. Orange points represent simulations for a random set of parameters (see text for details).