Time delay as a function of the wavelength for models with different lamppost height and for no BLR and for BLR contribution. For the BLR profile, we used a half-Gaussian, as shown in the middle panel of Fig. 2. Model parameters (top): black hole mass 10⁸ M_⊙, L/L_Edd = 1, inclination angle 30 degree, and luminosity of the corona is 10⁴⁰ erg s⁻¹. Model parameters (bottom): black hole mass 10⁸ M_⊙, L/L_Edd = 1, inclination angle 30 degree, and luminosity of the corona is 3.78 × 10⁴⁶ erg s⁻¹.