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

K. M. Rajwade; J. Tian; G. Younes; B. Posselt; B. Stappers; Z. Wadiasingh; E. D. Barr; M. C. Bezuidenhout; M. Caleb; F. Jankowski; M. Kramer; I. Pastor-Marazuela; M. Surnis

arXiv · 2505.02808

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

K. M. Rajwade·J. Tian·G. Younes·B. Posselt·B. Stappers·Z. Wadiasingh·E. D. Barr·M. C. Bezuidenhout·M. Caleb·F. Jankowski·M. Kramer·I. Pastor-Marazuela·M. Surnis

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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.

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K. M. Rajwade, J. Tian, G. Younes, B. Posselt, B. Stappers, Z. Wadiasingh, E. D. Barr, M. C. Bezuidenhout, M. Caleb, F. Jankowski, M. Kramer, I. Pastor-Marazuela, M. Surnis. 2025-05-05. A coherent radio burst from an X-ray neutron star in the Carina Nebula. https://arxiv.org/abs/2505.02808

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