Scaling relation between the L_AGN and black hole mass M_BH for GAEA-LC populations in the redshift range 0.9–1.8, following the same layout as Fig. 8. Additionally shown is the active sub-sample of the dust-attenuated population (orange contours) and its observability compared to the entire active population (orange percentages). For comparison, black lines show fractions of the Eddington limit: 1 L_edd (solid), 0.1 L_edd (dashed), and 0.01 L_edd (dash-dotted).