Two-dimensional histogram distribution of simulated sources in one realisation of our X-ray AGN luminosity function sampling for a 22.7 deg² area on the sky (253, 297 sources in total). Each black contour encloses the fraction of sources indicated as a label. To each source belongs one X-ray spectral model uniquely defined by the source luminosity, redshift, power-law index Γ and absorbing column density N_H (Sect. 2.1).