Upper panel: radial selection functions, i.e., probability distribution functions for emission redshifts of photons, for Models I and II (see Table 1), assuming observational energy bands 3.0−3.2 keV and 3.3−3.5 keV with F_lim fixed to 10^-13 erg/s/cm². Lower panel: effective clustering bias as a function of redshift for Models I and II. For Model II, along with our default value M_eff = 10¹³   h^-1M_⊙, we also show cases with M_eff = 10^12.5 and 10^13.5, which cover the typical range of biasing values obtained in the literature. The points with error bars show bias measurements for X-ray selected AGN from the COSMOS field as determined by Allevato et al. (2011, see their Fig. 9 for further details).