The dipole aerial
Even is plasma absent, spinning neutron star will radiate if magnetic and rotation axes do not coincide.
This is the case of a ‘dipole aerial’
Notes:
Note that even if there is no plasma surrounding the neutron star, the star will radiate if the magnetic and rotation axes do not coincide due to ‘magnetic braking’. This is what is known as a dipole aerial.
The wave radiated from the magnetic poles has an angular frequency,w. A field of 1e8 Tesla can in fact explain the energy losses observed… ie. magnetic dipole radiation is the principal way in which pulsars emit.