Comparison between log L_acc values measured from excess continuum–fitting with slab emission models (Sect. 3.1.1), and values derived from emission line luminosity (L_line) measurements, using empirical L_line − L_acc calibration relationships from Alcalá et al. (2014). Error bars on the x-axis correspond to a typical uncertainty of 0.25 dex on the L_acc measurements from the multicomponent spectral fit; error bars on the y-axis follow from error propagation including uncertainties on the measured line fluxes, and uncertainties on the calibration relationships, as listed in Alcalá et al. (2014). Green lines connect multiple measurements for the same object. Light dotted lines delimit an area of ±0.3 dex around the equality line (dashed in gray on the diagram).