Magnetic field topology and plasma β = P∕P_mag in the xz-plane in the MU5AD run, when the sink mass is 15 M_⊙. Left panels: amplitude of the Alfvén velocity (blue colours) and the segments show the magnetic fields direction in the xz-plane. The colour-coding represents the ratio between the toroidal component of the magnetic fields over the total magnetic fields. Yellow-to-white segments exhibit strong toroidal fields with B_ϕ ∕B > 0.3. Right panels: maps of the plasma β = P∕P_mag with velocity vectors overplotted. The red regions are dominated by the thermal pressure, while the blue ones are dominated by the magnetic pressure.