Changes in Polarization Position Angle across the Eclipse in the Double Pulsar System

TL;DR

This study examines polarization angle variations during eclipse in the Double Pulsar system, attributing changes to synchrotron absorption and Faraday rotation, and finds charge densities consistent with theoretical models.

Contribution

It provides the first detailed analysis of polarization angle changes during eclipse in the Double Pulsar system, linking observations to magnetospheric physics.

Findings

Polarization angle changes are ~2σ at 20 cm during eclipse.

Changes are consistent with differential synchrotron absorption.

Post-eclipse angle shifts suggest Faraday rotation in pulsar B's magnetotail.

Abstract

We investigate the changes in polarization position angle in radiation from pulsar A around the eclipse in the Double Pulsar system PSR J0737-3039A/B at the 20 cm and 50 cm wavelengths using the Parkes 64-m telescope. The changes are ~2\sigma\ during and shortly after the eclipse at 20 cm but less significant at 50 cm. We show that the changes in position angle during the eclipse can be modelled by differential synchrotron absorption in the eclipse regions. Position angle changes after the eclipse are interpreted as Faraday rotation in the magnetotail of pulsar B. Implied charge densities are consistent with the Goldreich-Julian density, suggesting that the particle energies in the magnetotail are mildly relativistic.