Radio emission of the Crab and Crab-like pulsars

Abstract

The pulsar radio emission is commonly associated with the plasma outflow in the open field line tube; then a pencil beam is emitted along the pulsar magnetic axis. Observations suggest that there is an additional radio emission mechanism specific for pulsars with high magnetic field at the light cylinder. These pulsars are known to be strong sources of non-thermal highenergy radiation, which could be attributed to reconnection in the current sheet separating, just beyond the light cylinder, the oppositely directed magnetic fields. Pulsars with the highest magnetic field at the light cylinder (>100 kG) exhibit also radio pulses in phase with the high-energy pulses. Moreover, giant radio pulses are observed in these pulsars. I argue that the reconnection process that produces high-energy emission could also be responsible for the radio emission. Namely, coalescence of magnetic islands in the sheet produces magnetic perturbations that propagate away in the form of electromagnetic nano-shots. I estimate the parameters of this emission and show that they are compatible with observations.