However, Lewis and his collaborators have shown that although the unpulsed radio emission from PSR B1259-63 is synchrotron radiation, it cannot be produced by particles from the pulsar wind. They argue that the emission comes from electrons from the Be star disk which are accelerated at a shock wave produced as the pulsar crashes through the disk. The characteristic twin peaked structure of the unpulsed radio brightness variation arises as the pulsar plows through the disk just before its closest approach to the Be star producing the first peak, disappears behind the disk for a short time, and then plows back through the disk on the other side of the star. Also indicated is the pulsar wind interacting with the disk, and the pulsar orbit, the dashed part of which is behind the plane of the sky. A remarkable series of observations was made of the pulsed radio emission from PSR B1259-63 on 12 March 1997.
Electromagnetic radiation consists of oscillating electric and magnetic fields.
The linear and circular polarization characteristics of the emission from pulsars are generally very stable and provide important clues to the structure of the source of the emission. The figure below shows the total intensity, and the linear and circular polarization of PSR 1259-63 during four observations taken one hour apart just before the pulsar disappeared behind the Be star disk. Amazingly, although the total intensity did not change, the linear and circular polarizations varied rapidly, an effect which has never been seen in any other pulsar. Simon and his collaborators believe that the linear polarization is being converted to circular polarization as the radiation passes through the highly-magnetized wind of the Be star. Modeling of the system is currently underway with a view to determining the structure of the stellar wind.