Left panel: gas number density n_g of the considered MHD simulation in the mid-plane parallel to the symmetry axis of the outflow lobes. Middle panel: corresponding dust temperature T_g. The dust temperature was post-processed to account for the stellar contribution of the protostars to dust heating (see Sect. 4 for details). Right panel: 3D magnetic field distribution. The characteristic helical component is in the interior of the outflow lobes that are embedded within a large-scale hourglass-shaped field. The box has edge lengths of 9200 AU.