Fig. 6

Phase portraits on the sheets $S_2^r$ and $S_3^r$ of the critical manifold S near the fold $F_3$. Panel (a) shows a projection onto the $(m_{\mathrm{SO}},V)$-plane of a trajectory of the desingularised slow flow (11), which converges to an attracting focus on $F_3$ (grey line), and panel (b) shows projected trajectories of the slow flow (9). The repelling and attracting nature of $F_3$ is indicated by light- and dark-green colours, respectively.