Kinematic analysis of the Iso-NBody simulation, at t = 7 Gyr. The contours represent the regions where δρ_r = 0 (in black) and δρ_r = ± 0.2 (in white). We show ⟨V_R⟩ (left column), ⟨V_ϕ⟩ (middle column), and V_{Z, br} (right column). First row: kinematic maps of the stellar component. Second row: kinematic maps of the DM component. Third row: radial profile of the kinematic amplitude of the Fourier mode (A₂) for the stellar (solid ochre) and DM (dashed grey) components. Fourth row: radial profile of the phase difference between each kinematic mode (ϕ₂) and the stellar spiral in density (ϕ₂(ρ_Stars)). The co-rotation radii of the spirals (R_{C R} ∼ 10 kpc) is shown as a vertical red strip.