1D radial profiles of the velocity perturbations resulting from the large, m = 2 impact simulation shown in Figure 2. These profiles show V_R (top row) and ∆V_ϕ (bottom row) as a function of radius R, at the same four times (t = 0, 0.4, 0.8, and 1.2 Gyr). The profiles are averaged on small radial bins at fixed azimuth (ϕ = 0°, corresponding to the dashed-dot regions in Figure 2). The solid black lines represent the results from the large impact simulation. The dashed blue lines show the velocity profiles resulting from the dominant Ω − κ/m wave (specifically the Ω − κ/2 wave for m = 2) in a small impact simulation (extracted from the blue curves in Fig. A.1), scaled up for comparison. These black 1D profiles reveal the characteristic triangular wave shape in V_R and the sawtooth pattern in ∆V_ϕ, which are key signatures of the non-linear velocity structures generated by the large initial perturbation.