An alternative technique for timing the double pulsar system

TL;DR

This paper proposes a new timing technique for the double pulsar system PSR J0737-3039A/B, utilizing a kinematic effect similar to Earth's day differences to determine the pulsar's rotation sense.

Contribution

It introduces an alternative method based on kinematic effects to determine the rotation direction of pulsars in a binary system, complementing previous techniques.

Findings

The kinematic effect causes a measurable frequency offset in B's modulation.

This offset can be used to determine the sense of A's rotation.

The method helps confirm the lighthouse model of pulsar emission.

Abstract

Freire et al. (2009, MNRAS, 396, 1764) have put forward a technique for timing the double pulsar system PSR J0737-3039A/B (hereafter A and B, respectively). Their technique can be used to determine the sense of rotation of A relative to its orbital plane. In this paper, we present another technique with the same purpose. Two well-known periods, the sidereal day and solar day, are often used to define the spin period of the earth. Their difference is caused by a kinematic effect which correlated with earth's rotation and revolution. We think that this kinematic effect should exist in the double pulsar system and can be used to determine the sense of rotation of the pulsars. Commonly, B's modulation frequency is considered to be equal to A's rotation frequency, because B's signal is modulated by A's energy flux. When the kinematic effect is considered, B's modulation frequency will be, similar to the solar day and sidereal day, a little higher or lower than A's rotation frequency. If this frequency offset can be found, A's rotation sense will be determined and the position of the lighthouse model will be consolidated.