The magnetic field topology in the reconnecting pulsar magnetosphere (Research Note)

Abstract

We show that toroidal magnetic field annihilation in the equatorial current sheet of the pulsar magnetosphere is related to how fast poloidal magnetic field lines close as we move away from the light cylinder. This determines the radial reconnection electric field which directly accelerates particles in the neutral layer inside the equatorial current sheet. The efficiency of the poloidal magnetic field closure near the light cylinder may be measurable through the pulsar braking index. We argue that the lower the efficiency of pair formation, the higher the braking index. We also argue that the synchrotron radiation reaction in the neutral layer does not inhibit the accelerated particles from reaching the maximum energy of about ∼1016 eV that is available in the open pulsar magnetosphere. © ESO 2007.