Space-time diagrams showing the evolution of the logarithm of the gas surface density Σ for the nine runs divided in four groups of different planet masses. The top plot of each group has the lowest magnetization, whereas the bottom plot has the highest. The radial extent of all the diagrams range from 0.5 to 1.5 code units, with the planet at R = 1. We pinpoint as ℰ₁ and ℰ₂ two episodes in the run Mj-β₃ that will be discussed in Sect. 3.2.3.