Rapid spin changes around a magnetar fast radio burst

Chin-Ping Hu^1*, Takuto Narita³, Teruaki Enoto^2,3, George Younes⁴, Zorawar Wadiasingh^4,5,6, Matthew G. Baring⁷, Wynn C. G. Ho⁸, Sebastien Guillot⁹, Paul S. Ray¹⁰, Tolga Guver^11,12, Kaustubh Rajwade¹³, Zaven Arzoumanian⁴, Chryssa Kouveliotou¹⁴, Alice K. Harding¹⁵, KeithC. Gendreau⁴

¹Department of Physics, National Changhua University of Education, Taiwan
²Extreme Natural Phenomena RIKEN Hakubi Research Team, RIKEN, Japan
³Department of Physics, Kyoto University, Japan
⁴Astrophysics Science Division, NASA Goddard Space Flight Center, USA
⁵Department of Astronomy, University of Maryland College Park, USA
⁶Center for Research and Exploration in Space Science and Technology, NASA Goddard Space Flight Center, USA
⁷Department of Physics and Astronomy, Rice University, USA
⁸Department of Physics and Astronomy, Haverford College, USA
⁹Institut de Recherche en Astrophysique et Planetologie, UPS-OMP, France
¹⁰Space Science Division, U.S. Naval Research Laboratory, USA
¹¹Department of Astronomy and Space Sciences, Istanbul University, Turkey
¹²Observatory Research and Application Center, Istanbul University, Turkey
¹³ASTRON, the Netherlands Institute for Radio Astronomy, Netherlands
¹⁴The George Washington University, USA
¹⁵Theoretical Division, Los Alamos National Laboratory, USA

* Presenter:Chin-Ping Hu, email:cphu0821@gm.ncue.edu.tw

Magnetars are neutron stars with extremely high magnetic fields that exhibit various X-ray phenomena such as sporadic sub-second bursts, long-term persistent flux enhancements, and variable rotation period derivative. In 2020, a fast radio burst (FRB), akin to cosmological millisecond-duration radio bursts, was detected from the Galactic magnetar SGR 1935+2154, confirming the long-suspected association between some FRBs and magnetars. However, the mechanism for FRB generation in magnetars remains unclear. Here we report the X-ray discovery of an unprecedented double glitch in SGR 1935+2154 within a time interval of approximately nine hours, bracketing an FRB that occurred on October 14, 2022. Each glitch involved a significant increase in the magnetar's spin frequency, being among the largest abrupt changes in neutron star rotation ever observed. Between the glitches, the magnetar exhibited a rapid spin-down phase, accompanied by a profound increase and subsequent decline in its persistent X-ray emission and burst rate. We postulate that a strong, ephemeral, magnetospheric wind provides the torque that rapidly slows the star's rotation. The trigger for the first glitch couples the star's crust to its magnetosphere, enhances the various X-ray signals, and spawns the wind that alters magnetospheric conditions that might produce the FRB.

Keywords: magnetars, fast radio bursts, neutron stars