Relative rotational level populations (left), cumulative total rotational opacities (middle), and excitation temperatures (right) for the hyperfine components of the J = 1 → 0 transition for the different σ_nth profiles described in Fig. B.2. Blue lines correspond to the profile in Eq. (6), red lines to a linear function for σ_nth profile, and the orange lines correspond to constant σ_nth.