The origin of fast radio bursts (FRBs), the brightest cosmic radio explosions, is still unknown. Bearing critical clues to FRBs' origin, the long-term evolution of FRBs has yet to be confirmed, since the field is still young and most FRBs were seen only once. Here we report clear evidence of decadal evolution of FRB~20121102A, the first precisely localized repeater. In conjunction with archival data, our FAST and GBT monitoring campaign since 2020 reveals a significant 7% decline of local dispersion measure (DM). The rotation measure (RM) of 30,755±16 radm−2 detected in the last epoch represents a 70% decrease compared to that from December 2016. The σRM parameter, which describes the complexity of the magneto-ionic environment surrounding the source, was shown to have decreased by 13%. These general trends reveal an evolving FRB environment, which could originate from an early-phase supernova associated with an enhanced pair wind from the FRB central engine.
@article{arxiv.2507.15790,
title = {Decadal evolution of a repeating fast radio burst source},
author = {P. Wang and J. S. Zhang and Y. P. Yang and D. K. Zhou and Y. K. Zhang and Y. Feng and Z. Y. Zhao and J. H. Fang and D. Li and W. W. Zhu and B. Zhang and F. Y. Wang and Y. F. Huang and R. Luo and J. L. Han and K. J. Lee and C. W. Tsai and Z. G. Dai and H. Gao and X. P. Zheng and J. H. Cao and X. L. Chen and E. Gugercinoglu and J. C. Jiang and W. C. Jing and Y. Li and J. Li and W. J. Lu and J. W. Luo and F. Lyu and C. C. Miao and C. H. Niu and J. R. Niu and Y. Qu and W. Y. Wang and Y. D. Wang and Y. B. Wang and C. J. Wang and Q. Wu and Y. S. Wu and S. M. Weng and D. Xiao and H. Xu and J. M. Yao and C. F. Zhang and R. S. Zhao and Q. Z. Liu and J. Zhang and D. J. Zhou and L. Zhang and Y. H. Zhu},
journal= {arXiv preprint arXiv:2507.15790},
year = {2025}
}
Comments
85 pages, 14 figures, under review of Nature Astronomy