Evidence for a parsec scale X-ray jet from the accreting neutron star Circinus X-1

TL;DR

This paper reports the first detection of an extended X-ray jet from the neutron star Circinus X-1, indicating a powerful jet capable of inflating large-scale radio structures, based on Chandra observations.

Contribution

It provides the first evidence of a parsec-scale X-ray jet from a neutron star, expanding understanding of jet phenomena in such systems.

Findings

Detection of an X-ray excess aligned with the radio counter-jet.

The inferred jet power exceeds the minimum needed to inflate the radio nebula.

Circinus X-1 is the first neutron star with an observed extended X-ray jet.

Abstract

We analyzed the zero-order image of a 50 ks Chandra gratings observation of Circinus X-1, taken in 2005 during the source's low-flux state. Circinus X-1 is an accreting neutron star that exhibits ultra-relativistic arcsecond-scale radio jets and diffuse arcminute-scale radio jets and lobes. The image shows a clear excess along the general direction of the north-western counter-jet, coincident with the radio emission, suggesting that it originates either in the jet itself or in the shock the jet is driving into its environment. This makes Circinus X-1 the first neutron star for which an extended X-ray jet has been detected. The kinetic jet power we infer is significantly larger than the minimum power required for the jet to inflate the large scale radio nebula.