Top left panel: mean sample time-lag spectrum for the LS102.4 light curves in experiment CD3 (continuous black line). The black dashed line indicates the model time-lag spectrum. Top right and bottom panels: the probability distribution of the phase-lag estimates at the frequencies indicated by the vertical dashed lines in the top-left panel. The solid and dashed vertical line in these panels indicate the model and sample mean phase-lag value at these frequencies, respectively.