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

Thumbnail Image

Files

2411.16606v2.pdf (4.89 MB)

Links to Files

http://arxiv.org/abs/2411.16606

Permanent Link

https://doi.org/10.48550/arXiv.2411.16606
 http://hdl.handle.net/11603/37900

Collections

UMBC Faculty Collection
UMBC Center for Space Sciences and Technology (CSST) / Center for Research and Exploration in Space Sciences & Technology II (CRSST II)

Author/Creator

Author/Creator ORCID

https://orcid.org/0000-0002-7991-028X

Date

2024-11-26

Type of Work

journal articles
preprints
Text

Department

Program

Citation of Original Publication

Rights

This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain

Subjects

Astrophysics - High Energy Astrophysical Phenomena

Abstract

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 ≳ 0.5 Myr old magnetar with a ≳ 10¹³ 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 ~10³³ erg/s associated with exceptionally bright coherent radio emission.