Detection of X-ray emission from a bright long-period radio transient.

Nature (2025)

Authors:

Ziteng Wang, Nanda Rea, Tong Bao, David L Kaplan, Emil Lenc, Zorawar Wadiasingh, Jeremy Hare, Andrew Zic, Akash Anumarlapudi, Apurba Bera, Paz Beniamini, AJ Cooper, Tracy E Clarke, Adam T Deller, JR Dawson, Marcin Glowacki, Natasha Hurley-Walker, SJ McSweeney, Emil J Polisensky, Wendy M Peters, George Younes, Keith W Bannister, Manisha Caleb, Kristen C Dage, Clancy W James, Mansi M Kasliwal, Viraj Karambelkar, Marcus E Lower, Kaya Mori, Stella Koch Ocker, Miguel Pérez-Torres, Hao Qiu, Kovi Rose, Ryan M Shannon, Rhianna Taub, Fayin Wang, Yuanming Wang, Zhenyin Zhao, ND Ramesh Bhat, Dougal Dobie, Laura N Driessen, Tara Murphy, Akhil Jaini, Xinping Deng, Joscha N Jahns-Schindler, YW Joshua Lee, Joshua Pritchard, John Tuthill, Nithyanandan Thyagarajan

Abstract:

Recently, a class of long-period radio transients (LPTs) has been discovered, exhibiting emission thousands of times longer than radio pulsars1-5. These findings, enabled by advances in wide-field radio surveys, challenge existing models of rotationally powered pulsars. Proposed models include highly magnetized neutron stars6, white-dwarf pulsars7 and white-dwarf binary systems with low-mass companions8. Although some models predict X-ray emission6,9, no LPTs have been detected in X-rays despite extensive searches1-5,10. Here we report the discovery of an extremely bright LPT (10-20 Jy in radio), ASKAP J1832-0911, which has coincident radio and X-ray emission, both with a 44.2-minute period. Its correlated and highly variable X-ray and radio luminosities, combined with other observational properties, are unlike any known Galactic object. The source could be an old magnetar or an ultra-magnetized white dwarf; however, both interpretations present theoretical challenges. This X-ray detection from an LPT reveals that these objects are more energetic than previously thought and establishes a class of hour-scale periodic X-ray transients with a luminosity of about 1033 erg s-1 linked to exceptionally bright coherent radio emission.

A Coherent Radio Burst from an X-Ray Neutron Star in the Carina Nebula

The Astrophysical Journal Letters American Astronomical Society 985:1 (2025) L3-L3

Authors:

KM Rajwade, J Tian, G Younes, B Posselt, B Stappers, Z Wadiasingh, ED Barr, MC Bezuidenhout, M Caleb, F Jankowski, M Kramer, I Pastor-Marazuela, M Surnis

Abstract:

Abstract The neutron star zoo comprises several subpopulations 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 J104608.7−594306 in 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 subpopulation of neutron stars.

Relativistic ejecta from stellar mass black holes: insights from simulations and synthetic radio images

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 540:1 (2025) 1084-1106

Authors:

Katie Savard, James H Matthews, Rob Fender, Ian Heywood

The Ejection of Transient Jets in Swift J1727.8−1613 Revealed by Time-dependent Visibility Modeling

The Astrophysical Journal Letters American Astronomical Society 984:2 (2025) l53

Authors:

Callan M Wood, James CA Miller-Jones, Arash Bahramian, Steven J Tingay, He-Xin Liu, Diego Altamirano, Rob Fender, Elmar Körding, Dipankar Maitra, Sera Markoff, David M Russell, Thomas D Russell, Craig L Sarazin, Gregory R Sivakoff, Roberto Soria, Alexandra J Tetarenko, Valeriu Tudose

The origin of the very-high-energy radiation along the jet of Centaurus A

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 539:4 (2025) 3697-3713

Authors:

Cainã de Oliveira, James H Matthews, Vitor de Souza