High-energy radiation from the pulsar equatorial current sheet

Pulsars emit beams of radiation that reveal the extreme physics of neutron star magnetospheres. However, our understanding is incomplete. Recent global particle-in-cell (PIC) simulations have raised several questions that led us to question their validity and their extrapolation to realistic particle Lorentz factors, and electric and magnetic fields. Our aim was to generate realistic sky maps of high-energy radiation from first principles. We propose a novel method to study the equatorial current sheet (ECS) where most of the particle acceleration and the high-energy radiation is expected to originate. We first determined its shape and external magnetic field with a steady-state ideal force-free solution. Then, we considered the extra electric and magnetic field components that develop when dissipation is considered. Finally, we studied the particle acceleration and radiation that is due to these extra field components for realistic field and particle parameters. We generated realistic sky maps of high-energy radiation and compared them with those obtained via PIC simulations. These sky maps may also be closely reproduced using the ECS of the split-monopole solution beyond the light cylinder. The ECS is probably stabilized by the normal magnetic field component that is due to the global magnetospheric reconnection. Our method helps us better understand the origin of the pulsed high-energy radiation in the pulsar magnetosphere.