Models of VDFs: bi-Kappa from Eq. (2) with 2θ_⊥/c = θ_∥/c = 0.02 (dashed blue lines) and κ = 9/4, and bi-Maxwellian limits (κ → ∞) with the same temperature (Maxwellian-H with dash-dotted lines) or with a lower temperature (Maxwellian-C with solid lines). Parallel cuts F(v_∥) are shown in panela), and isocontours at 4 × 10^-3 in panelb) and 10^-2 in panelc), corresponding to dotted lines in panela). Notice the difference between the Maxwellian limits.