The origin of the X-ray-emitting object moving away from PSR B1259-63

TL;DR

This paper proposes that a high-speed pulsar-stellar wind outflow, loaded with stellar wind near periastron, explains the observed moving X-ray feature from PSR B1259-63, suggesting a jet-like structure and specific wind thrust ratios.

Contribution

It introduces a novel model of a pulsar-stellar wind outflow as the origin of the moving X-ray object, linking wind interactions to observable features.

Findings

The outflow moves away from the binary at high speed.

The outflow is periodically loaded with stellar wind near periastron.

The model implies pulsar-to-stellar wind thrust ratios of about 0.1.

Abstract

A mysterious X-ray-emitting object has been detected moving away from the high-mass gamma-ray binary PSR B1259-63, which contains a non-accreting pulsar and a Be star whose winds collide forming a complex interaction structure. Given the strong eccentricity of this binary, the interaction structure should be strongly anisotropic, which together with the complex evolution of the shocked winds, could explain the origin of the observed moving X-ray feature. We propose here that a fast outflow made of a pulsar-stellar wind mixture is always present moving away from the binary in the apastron direction, with the injection of stellar wind occurring at orbital phases close to periastron passage. This outflow periodically loaded with stellar wind would move with a high speed, and likely host non-thermal activity due to shocks, on scales similar to those of the observed moving X-ray object. Such an outflow is thus a very good candidate to explain this X-ray feature. This, if confirmed, would imply pulsar-to-stellar wind thrust ratios of $\sim 0.1$, and the presence of a jet-like structure on the larger scales, up to its termination in the ISM.