Power spectrum P(k) computed for sideband regions above the Lyα forest region for different λ windows. Each λ region corresponds to one redshift bin. The top and bottom plots correspond respectively to the two sidebands defined in the rest frame by 1270 < λ_RF < 1380 Å and 1410 < λ_RF < 1520 Å. Each power spectrum is fitted by the product of the sixth-degree polynomial obtained in Fig. 18 and a first-degree polynomial in which the 2 parameters are free.