(a) Corona luminosity as a function of the accretion disk luminosity. (b) Ratio of the corona luminosity to the bolometric luminosity against the ratio of the bolometric luminosity to the Eddington luminosity. For PKS 1502+036 and PMN J0948+0022, only upper limits of the corona luminosity (L_corona = 0.58 × L_d) are present, since no significant corona emission is observed in their SEDs. The data of RQ BLS1 and NLS1 galaxies are taken from Wang et al. (2004).