Top row: m = 2 power spectra in log scale as a function of radius for RunC. The time windows are 3.16−4.24 Gyr (left panel), 6.32−8.48 Gyr (middle), and 8.38−10.54 Gyr (right). The vertical scales give values of Ω in Myr⁻¹ (left) and in km s⁻¹ kpc⁻¹ (right). The radial scale (in kpc) is converted in L_z using the circular rotation curve. The mean curves Ω ± κ/2 are drawn as black short-dashed lines, Ω ± κ/4 as dot-dashed lines, Ω as a solid line (for the CR), and Ω + κ as a triple-dot-dashed line. The uppermost full horizontal line represents the mean bar pattern speed Ω_B = 21.9−14.2 (full line), which was determined directly from the time variation of the bar position-angle. The lowest one is an estimated intermittent waves packet Ω_oW ≈ 4.4−2.6 km s⁻¹ kpc⁻¹. The intermediate wave at Ω_iS ≈ 13.2−8.4 km s⁻¹ kpc⁻¹ is computed as a beat mode. Bottom row: same, but for m = 4.