A dynamic magneto-ionic environment around a long-period radio transient

@misc{li2026dynamic,
  title = {{A dynamic magneto-ionic environment around a long-period radio transient}},
  author = {Botao Li and Yongjie Jin and Shike Qu and Chaohua Gao and Wei Wang and Pei Wang and Shumei Jia and Jifeng Liu},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.23259},
  eprint = {2609.23259},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.23259},
}

TY  - UNPB
TI  - A dynamic magneto-ionic environment around a long-period radio transient
AU  - Botao Li
AU  - Yongjie Jin
AU  - Shike Qu
AU  - Chaohua Gao
AU  - Wei Wang
AU  - Pei Wang
AU  - Shumei Jia
AU  - Jifeng Liu
PY  - 2026
DA  - 2026/09/20
PB  - arXiv
DO  - 10.48550/arxiv.2609.23259
UR  - https://arxiv.org/abs/2609.23259
AB  - Faraday rotation provides one of the most direct probes of magnetized plasma along the line of sight, from the large-scale Galactic magnetic field to compact plasma environments local to radio sources. In particular, temporal variations in rotation measure can trace changes in the density, magnetic-field strength, or geometry of the Faraday-rotating medium, as observed in radio pulsars and fast radio bursts. Long-period radio transients (LPTs), a recently identified class of coherent radio sources with periods of hundreds to thousands of seconds, remain poorly explored because their physical nature is still uncertain. Here we present full-Stokes observations of the 421-s LPT source CHIME J0630+25 and report, for the first time, extreme rotation measure (RM) variability from approximately -400 to -1630 rad m^-2. The rapid RM changes occur on short timescales, including a difference of approximately 50 rad m^-2 between two consecutive rotation periods and a sudden change of approximately 536 rad m^-2 within approximately 2500 s. Compared with other radio-emitting sources, CHIME J0630+25 occupies an unusual region of the DM-RM plane: despite its very small DM of approximately 22 pc cm^-3, |RM| reaches over 1.6 x 10^3 rad m^-2, far exceeding that expected from the interstellar medium and pulsars. The fast and large-amplitude RM variations should arise from a compact, structured, and rapidly evolving magneto-ionic environment local to the source, possibly associated with a compact binary system.
ER  -