The energy dependence of the PSD parameters of NGC 4051. The solid black squares show the best-fit, BPL model parameters plotted as a function of energy for NGC 4051. Open red squares and open blue circles show the respective results from Rani et al. (2025), and from McHardy et al. (2004), respectively. The solid lines indicate the weighted PSD_amp of the four lowest energy points in the left panel, the best-fit log-linear model to the α_high − E data in the middle panel, and the weighted bending frequency in the right panel. Note that, for comparison reasons, the y axis limits are the same in the relevant panels in this figure and in Fig. 5.