A coherent radio burst from an X-ray neutron star in the Carina Nebula

TL;DR

This paper reports the first detection of a coherent radio burst from a known radio-quiet X-ray neutron star, revealing a possible link between different neutron star populations and suggesting common emission mechanisms.

Contribution

It presents the discovery of a rare radio burst from a thermally emitting neutron star, bridging the gap between radio-quiet and radio-emitting neutron star populations.

Findings

Detected a unique radio burst from a radio-quiet neutron star.

Suggests a physical link between different neutron star populations.

Highlights the need for regular monitoring of radio-quiet neutron stars.

Abstract

The neutron star zoo comprises several sub-populations that range from energetic magnetars and thermally emitting X-ray neutron stars to radio-emitting pulsars. Despite studies over the last five decades, it has been challenging to obtain a clear physical link between the various populations of neutron stars, vital to constrain their formation and evolutionary pathways. Here we report the detection of a burst of coherent radio emission from a known radio-quiet, thermally emitting neutron star 2XMM J104608.7$-$594306in the Carina Nebula. The burst has a distinctive sharp rise followed by a decay made up of multiple components, which is unlike anything seen from other radio-emitting neutron stars. It suggests an episodic event from the neutron star surface, akin to transient radio emission seen from magnetars. The radio burst confirms that the X-ray source is a neutron star and suggests a new link between these apparently radio-quiet X-ray emitting sources and other transient or persistent radio-emitting neutron stars. It also suggests that a common physical mechanism for emission might operate over a range of magnetic field strengths and neutron star ages. We propose that 2XMM J104608.7$-$594306 straddles the boundary between young, energetic neutron stars and their evolved radio-emitting cousins and may bridge these two populations. The detection of such a radio burst also shows that other radio-quiet neutron stars may also emit such sporadic radio emission that has been missed by previous radio surveys and highlights the need for regular monitoring of this unique sub-population of neutron stars.