The double pulsar: evolutionary constraints from the system geometry

TL;DR

This paper analyzes the double pulsar system PSR J0737-3039A/B to constrain its system geometry, providing insights into its evolutionary history and the supernova event that formed the second pulsar.

Contribution

It presents six years of pulse profile data analysis to constrain the system's geometry, supporting a symmetric supernova formation scenario.

Findings

Low misalignment angle of the pulsar's spin and orbital axes (<6.1°)

Evidence for a relatively symmetric supernova event

Constraints on the system's evolutionary pathway

Abstract

The double pulsar system PSR J0737-3039A/B is a highly relativistic double neutron star (DNS) binary, with a 2.4-hour orbital period. The low mass of the second-formed NS, as well the low system eccentricity and proper motion, point to a different evolutionary scenario compared to other known DNS systems. We describe analysis of the pulse profile shape over 6 years of observations, and present the resulting constraints on the system geometry. We find the recycled pulsar in this system, PSR J0737-3039A, to have a low misalignment between its spin and orbital angular momentum axes, with a 68.3% upper limit of 6.1 degrees, assuming emission from both magnetic poles. This tight constraint lends credence to the idea that the supernova that formed the second pulsar was relatively symmetric, possibly involving electron-capture onto an O-Ne-Mg core.