Understanding the nature of Partially Screened Gap in Pulsars from Subpulse Drifting
Abstract
The radio emission from pulsars is expected to arise as a result of instabilities developing in a non-stationary plasma moving along the open magnetic field lines. The out-flowing plasma is setup due to a series of sparking discharges in an inner acceleration region (IAR) above the neutron star polar cap. The sparking process is thermally regulated due to discharge of ions from the heated polar cap surface that makes the IAR a partially screened gap (PSG). The magnetic field near the pulsar surface is highly non-dipolar in nature and the sparks undergo variable ExB drift in the IAR seen as the well known phenomenon of subpulse drifting in the single pulse stacks. In this talk we will highlight the observational features of subpulse drifting in the pulsar population. We will also discuss how the drifting behaviour can be be used to understand the sparking process in the framework of the Partially Screened Gap in non-dipolar magnetic fields.