Demonstration of how the condition for axisymetric modes (κ²/πGρ < 1) is satisfied at the equator in some time steps, considering both cases with (solid lines) and without (dashed inset curves) self-gravity. ‘Homo’ and ‘InHomo’ refer to homogeneous and inhomogeneous structures, respectively. We note the logarithmic scale on the vertical axis. Models are labelled in all panels with symbols referring to Table A.1.