Slide 49 of 59
Notes:
Brightening on the boundaries between closed and open field lines could give rise to the subpulses. As the star rotates, the brightening moves across our line of sight.
The brightening may be caused by the presence of current sheets between the closed and open lines. Such lines do not lie in the same plane because the open ones are distorted by the rotation of the neutron star. Current sheets originate where the lines change direction.