Distribution of the gas velocity modulus and the magnetic-field lines for two models: on the left panel, E_tot = 3 × 10⁵⁵ erg at a time t = 2.3 Myr; on the right panel, E_tot = 10⁵⁵ erg at t = 3.4 Myr. The velocity is presented in units of 10⁸ cm/s and the magnetic-field strength (shown in colour) in units of 400 μG.