Comparison between the molecular hydrogen column density ($N_{{\text{H}}_2}$) and the observed Fe Kα signal of the illuminated clouds in the CMZ. The Fe Kα signal represents the time-integrated observed surface rate (i.e., the area under the light curves shown in Fig. 4), rescaled by multiplying it by the square of the physical distance (R²) between the cloud and Sgr A^⋆. The lines show the theoretical predictions for different values of total emitted energy in the 2–10 keV band. The $N_{{\text{H}}_2}$ values are derived from the map published by Battersby et al. (2024). Data for Sgr B2 and Sgr C are taken from Terrier et al. (2010, 2018); Chuard et al. (2018). Data for the CND, from Stel et al. (2023), reflect its response to the significantly weaker flare from the magnetar SGR J1745-2900.