Top left: an example of a transfer function obtained using model M3. Top right: comparison of velocity-binned time lags obtained from model M3 and CCF analysis. Bottom left: delay integral of the transfer function ﹩{\rm{\Psi }}(v)﹩, superposed on the observed, scaled mean Hβ profile. Shaded areas represent the 1σ error band. Bottom right: velocity integral of the transfer function ﹩{\rm{\Psi }}(\tau )﹩. Shaded areas represent the 1σ error band. The dashed line represents the CCF between the observed light curves of the continuum and Hβ fluxes.