Results of the anisotropic and axisymmetric velocity model for the atomic gas in Messier 33 (100 pc resolution data). Results are those of the one-parameter model and show the profile of σ_R (σ_ϕ, respectively) as filled green circles (open diamonds), obtained assuming σ_ϕ = σ_z = ⟨σ_los⟩_ϕ (σ_R = σ_z = ⟨σ_los⟩_ϕ). A dashed blue line is for ⟨σ_los⟩_ϕ (corrected from instrumental dispersion). Results obtained assuming a null thermal component. The shaded areas highlight the regions where the k = 2 mode was found to be weaker than other dispersion asymmetries (see Sect. 3).