Mapping the magnetosphere of PSR B1055-52

TL;DR

This study geometrically analyzes PSR B1055-52, revealing the inclination of its magnetic axis, emission heights, and challenging assumptions about pulsar magnetosphere structures based on radio and gamma-ray observations.

Contribution

It provides new insights into the emission geometry and magnetic inclination of PSR B1055-52, questioning the traditional view of closed magnetospheric regions in pulsars.

Findings

Magnetic axis inclined at 75 degrees to rotation axis.

Radio and gamma-ray emissions originate from different magnetic field regions.

Challenges the assumption of fully closed, quiescent magnetospheres in pulsars.

Abstract

We present a geometric study of the radio and gamma-ray pulsar B1055-52 based on recent observations at the Parkes radio telescope. We conclude that the pulsar's magnetic axis is inclined at an angle of 75 degrees to its rotation axis and that both its radio main pulse and interpulse are emitted at the same height above their respective poles. This height is unlikely to be higher or much lower than 700 km, a typical value for radio pulsars. It is argued that the radio interpulse arises from emission formed on open fieldlines close to the magnetic axis which do not pass through the magnetosphere's null (zero-charge) surface. However the main pulse emission must originate from fieldlines lying well outside the polar cap boundary beyond the null surface, and farther away from the magnetic axis than those of the outergap region where the single gamma-ray peak is generated. This casts doubt on the common assumption that all pulsars have closed, quiescent, corotating regions stretching to the light cylinder.