Top panel: results of fitting the w − ℓ dependence with w′−ℓ′ dependences computed for different inclination angles i and assuming constant relative flux over the NS surface (CRF case, see Fig. 8). The corresponding correction factors are (A_F, A_R) = (1.053, 0.856) for i = 0°, (1.1, 0.972) for 45°, and (1.15, 1.12) for 90°. Bottom panel: corresponding solutions at the (M, R) plane obtained assuming a non-rotating NS (dashed curve) and using additional correction factors A_F and A_R for different inclination angles.