Evolution of halo density angular modes for the three halo models calculated with the BPM code. The peak at ℓ = 3 (see footnote 2 ² for consistency with previous works) has the largest amplitude for Plummer (black) and NFW1 (blue) models at all times. However, the NFW2 (red) model shows an increasingly flatter spectrum. This is consistent with maps shown in Fig. 3, where the dipole has a comparable amplitude with the wake.