Examples of lag-spectra based on ICCF lag measurements using the complete light curves for three cases: original (left), detrended with order = 1 (middle), and detrended with order = 2 (right). The ICCF lag measurements (red circles) are shown in the rest-frame as a function of rest-frame wavelength. The dot-dashed red line represents the best-fit to the relation τ  ∝ λ^β using Equation (5), where τ₀, β, and α are free parameters. The dot-dashed black line shows the best-fit with fixed β = 4/3 and α = 1 with only τ₀ as a free parameter. Shaded regions indicate the 1σ uncertainties from the fitting. The blue and maroon dashed lines show the respective best-fits derived without including τ_uI in the lag-spectrum for the cases where all parameters (τ₀, β, and α) are free and where β = 4/3 and α = 1 are fixed. Vertical and horizontal dotted lines mark the rest-frame reference wavelength and zero rest-lag, respectively.