Eight spherical free-decay eigenfunctions B_i of the smallest decay rates. Each mode is either purely toroidal or purely poloidal. Top row: modes symmetric with respect to the mid-plane z = 0 (quadrupolar modes), while the modes in the bottom row are anti-symmetric (dipolar). For the poloidal modes, arrows represent the projection of the magnetic field on the (xy)-plane. For the toroidal modes, contours show the strength of the azimuthal component of the magnetic field with the normalisation Eq. (A.20). The decay rate of each mode γ is shown at the top of each panel.