Estimated ACF of the field ɡ_η0(y) for different values of ŋ₀ = ŋ in 3 different directions. Blue, purple and red lines represent respectively the x, y and π/4 (x = y) directions. Two top panels are for ŋ₀ = −1.06 and 0.69, whereas the two bottom panels are for ŋ₀ = 0.94 and 1.58. At low column-densities (η₀ = −1.06), a strong anisotropy is detected in the x-direction and becomes noticeable at x/L ≥ 2 × 10^–2 as was the case for the column-density ACF (see Fig. 7). For high column-densities (η₀ > 0), however, the anisotropy is subdued and the ACFs are fairly isotropic at small scales up to x/L, r/L ~ 10^–1 where the data become quite noisy. Green dashed lines show the profile of an isotropic ACF proportional to r^–1/2 that matches the data at short scales fairly well, at least over a decade.