Projections along directions identified by φ = 0 and θ = i(π/8) with i = 0,...,4 (from left to right, top to bottom) of a critical second-order rigidly rotating model with Ψ = 2; the first and the fifth panel represent the projections along the ẑ-axis (“face on”) and the -axis (“edge-on”) of the intrinsic coordinate system, respectively. Solid lines mark the isophotes, corresponding to selected values of Σ/Σ₀ in the range  [0.9,10^-7] . The last panel shows the ellipticity profiles, as functions of the semi-major axis of the projected image â_P, referred to the lines of sight considered in the previous panels (from bottom to top). Dots represent the locations of the isophotes and the arrow marks the position of the half-light isophote (practically the same for every projection considered in the figure).