Measurement of the azimuthal perturbation in each normalized quantity x, averaged over an azimuthal range of ϕ_peak ± 2h_p according to Eq. (19). Densities and temperatures are plotted in the left panel and velocities in the right. Open circles indicate non-accreting planets, and closed circles indicate those with accretion luminosity (see Sect. 4.2 for a discussion). At z/r ≈ θ = 0.2, where dust and gas are not well coupled, the plotted T_dust amplitude reflects the radial “pseudo-arm” (see the discussion in Sect. 3.4) rather than the Lindblad spiral.