L_{2 − 10 keV}/L_Hα − λ_Edd relation. We used the same colour code as Fig. 2. Solid black line is the best fitting linear relation considering the complete sample. We reported also the best fitting linear relation for the sub- (orange) and super- (green) Eddington sources. The stars represent the mean value in each λ_Edd bin and are shown for illustrative purposes only. Given the large intrinsic scatter (spanning ≥2 orders of magnitude in L_{2 − 10 keV}/Hα), these averages are not used for χ² minimisation or quantitative inference. A quadratic fit (dotted-dashed curve) is shown to illustrate curvature in the trend. This figure includes only low-redshift AGN with joint detections in both X-rays and Hα; no upper limits are included in this analysis.