Vacuum gap model for PSR B0943+10

¹ Institute of Astronomy, University of Zielona Góra, Lubuska 2, 65-265, Zielona Góra, Poland
² Center for Plasma Astrophysics, Abastumani Astrophysical Observatory, Al.Kazbegi ave. 2a, Tbilisi 380060, Georgia
³ Max-Planck Institute für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany

Corresponding author: J. A. Gil, jag@astro.ca.wsp.zgora.pl

Received: 27 November 2001
Accepted: 25 March 2002

Abstract

PSR B0943+10 is known to show remarkably stable drifting subpulses, which can be interpreted in terms of a circumferential motion of 20 sparks, each completing one circulation around the periphery of the polar cap in 37 pulsar periods. We use this observational constraint and argue that the vacuum gap model can adequately describe the observed drift patterns. Further we demonstrate that only the presence of strong non-dipolar surface magnetic field can favor such vacuum gap formation. Subsequently, for the first time we are able to constrain the parameters of the surface magnetic field, and model the expected magnetic structure on the polar cap of PSR B0943+10 considering the inverse Compton scattering photon dominated vacuum gap.