Close-ups of the propagation of a faster jet of plasma in a uniform medium at different times from the insertion time t = 0: t = 3.19, 3.82, 4.3, 8.46 h. From left to right in each row: Difference between the particle density n at time t and its initial value at t = 0, the wind radial velocity v_r, the radial component of magnetic field B_r, and the difference between the longitudinal magnetic field B_φ at time t and that at time t = 0, normalized by the initial absolute value of B_φ. A selection of magnetic field lines drawn near the centre of the perturbation are included (black arrowed lines). The position where the time profiles of Fig. 3 are taken is given (star). An animation is provided online.