Relation between the 0.5–8 keV X-ray photon index and the total number of counts, the 0.5–8 keV flux f _x , the 0.5–8 keV luminosity L _X , and the BH mass. No relation appears to exist between Γ and X-ray counts, while there are rather weak apparent negative correlations with f _x and L _X ; M _BH does not appear to correlate with Γ.