Detection of X-ray Emission from a Bright Long-Period Radio Transient

• Published in: arXiv.org 2024-11
• Main Authors: Wang, Ziteng, Rea, Nanda, Bao, Tong, Kaplan, David L, Lenc, Emil, Wadiasingh, Zorawar, Hare, Jeremy, Zic, Andrew, Anumarlapudi, Akash, Bera, Apurba, Paz Beniamini, Cooper, A J, Clarke, Tracy E, Deller, Adam T, Dawson, J R, Glowacki, Marcin, Hurley-Walker, Natasha, McSweeney, S J, Polisensky, Emil J, Peters, Wendy M, Younes, George, Bannister, Keith W, Caleb, Manisha, Dage, Kristen C, James, Clancy W, Kasliwal, Mansi M, Karambelkar, Viraj, Lower, Marcus E, Mori, Kaya, Stella Koch Ocker, Pérez-Torres, Miguel, Qiu, Hao, Kovi Rose, Shannon, Ryan M, Taub, Rhianna, Wang, Fayin, Wang, Yuanming, Zhao, Zhenyin, Bhat, N D R, Dobie, Dougal, Driessen, Laura N, Murphy, Tara, Jaini, Akhil, Deng, Xinping, Jahns-Schindler, Joscha N, Lee, Y W J, Pritchard, Joshua, Tuthill, John, Thyagarajan, Nithyanandan
• Format: Article
• Language: English
• Subjects: Binary stars; Companion stars; Luminosity; Magnetars; Magnetic properties; Neutron stars; Pulsars; Radio emission; Transients (astronomy); White dwarf stars; X-ray astronomy; X-rays
• ISSN: 2331-8422

Recently, a class of long-period radio transients (LPTs) has been discovered, exhibiting emission on timescales thousands of times longer than radio pulsars. Several models had been proposed implicating either a strong magnetic field neutron star, isolated white dwarf pulsar, or a white dwarf binary system with a low-mass companion. While several models for LPTs also predict X-ray emission, no LPTs have been detected in X-rays despite extensive searches. 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. The X-ray and radio luminosities are correlated and vary by several orders of magnitude. These properties are unique amongst known Galactic objects and require a new explanation. We consider a \(\gtrsim0.5\) Myr old magnetar with a \(\gtrsim 10^{13}\) G crustal field, or an extremely magnetised white dwarf in a binary system with a dwarf companion, to be plausible explanations for ASKAP J1832-0911, although both explanations pose significant challenges to formation and emission theories. The X-ray detection also establishes a new class of hour-scale periodic X-ray transients of luminosity \(\sim10^{33}\) erg/s associated with exceptionally bright coherent radio emission.