Existence boundaries of three cycle pairs (dashed lines) in the (Re,Rm) plane and critical Re_c(Rm), Rm_c(Re) of saddle nodes obtained by continuation (symbols). Black arrows indicate the regions in which the cycles exist. For SN₁, dark blue/black bullets correspond to low resolution results (24 × 12 × 36), and light blue/grey bullets are for double resolution (48 × 24 × 72). Inset: selected continuation curves of SN₁ at fixed Rm.