Plot of Γ against λ. A typical error is shown in the upper left-hand corner: the green solid error bar is the statistical error, the red dashed one corresponds to the total error on λ (which includes the uncertainty related to the virial method used to estimate the BH masses). The filled points (blue in the colour version) are sources with 0 ≤ z < 0.4, triangles (magenta in the colour version) are sources with 0.4 ≤ z < 0.8 and the stars (red in the colour version) are sources with 0.8 ≤ z < 2.