Radial profiles of angular velocities relative the Keplerian frequency Ω_⋆ ∝ r^−3/2 after averaging over 7.5t_in in run M3B10. The red area encompasses the bulk orbital velocity plus or minus the bulk sound speed. The thin blue curve is the spiral pattern speed estimated from the 2 ≤ m ≤ 6 Fourier modes. The thick black curve is the pattern speed estimated by maximizing the time correlation Eq. (24). The dashed green lines are contours of constant angular velocity.