_version_ 1866911036337029120
author Feng, Yi
Zhang, Yong-Kun
Xie, Jintao
Yang, Yuan-Pei
Qu, Yuanhong
Zhou, Dengke
Li, Di
Zhang, Bing
Zhu, Weiwei
Lu, Wenbin
Xu, Jiaying
Miao, Chenchen
Tian, Shiyan
Wang, Pei
Yao, Ju-Mei
Niu, Chen-Hui
Niu, Jiarui
Xu, Heng
Jiang, Jinchen
Zhou, Dejiang
Liu, Zenan
Tsai, Chao-Wei
Dai, Zigao
Wu, Xuefeng
Wang, Fayin
Han, Jinlin
Lee, Kejia
Xu, Renxin
Huang, Yongfeng
Zou, Yuanchuan
Cao, Jinhuang
Chen, Xianglei
Fang, Jianhua
Li, Dongzi
Li, Ye
Lu, Wanjin
Luo, Jiawei
Luo, Jintao
Luo, Rui
Lyu, Fen
Wang, Bojun
Wang, Weiyang
Wu, Qin
Xue, Mengyao
Xiao, Di
Yu, Wenfei
Yuan, Jianping
Zhang, Chunfeng
Zhang, Junshuo
Zhang, Lei
Zhang, Songbo
Zhao, Rushuang
Zhu, Yuhao
author_facet Feng, Yi
Zhang, Yong-Kun
Xie, Jintao
Yang, Yuan-Pei
Qu, Yuanhong
Zhou, Dengke
Li, Di
Zhang, Bing
Zhu, Weiwei
Lu, Wenbin
Xu, Jiaying
Miao, Chenchen
Tian, Shiyan
Wang, Pei
Yao, Ju-Mei
Niu, Chen-Hui
Niu, Jiarui
Xu, Heng
Jiang, Jinchen
Zhou, Dejiang
Liu, Zenan
Tsai, Chao-Wei
Dai, Zigao
Wu, Xuefeng
Wang, Fayin
Han, Jinlin
Lee, Kejia
Xu, Renxin
Huang, Yongfeng
Zou, Yuanchuan
Cao, Jinhuang
Chen, Xianglei
Fang, Jianhua
Li, Dongzi
Li, Ye
Lu, Wanjin
Luo, Jiawei
Luo, Jintao
Luo, Rui
Lyu, Fen
Wang, Bojun
Wang, Weiyang
Wu, Qin
Xue, Mengyao
Xiao, Di
Yu, Wenfei
Yuan, Jianping
Zhang, Chunfeng
Zhang, Junshuo
Zhang, Lei
Zhang, Songbo
Zhao, Rushuang
Zhu, Yuhao
contents In this study, we report multi-year polarization measurements of four repeating FRBs initially discovered by CHIME: FRBs~20190117A, 20190208A, 20190303A, and 20190417A. We observed the four repeating FRBs with FAST, detecting a total of 66 bursts. Two bursts from FRB~20190417A exhibit a circular polarization signal-to-noise ratio greater than 7, with the highest circular polarization fraction recorded at 35.7%. While the bursts from FRBs 20190208A and 20190303A are highly linearly polarized, those from FRBs~20190117A and 20190417A show depolarization due to multi-path propagation, with σ_{\mathrm{RM}} = 2.78 \pm 0.05 rad m$^{-2}$ and 5.19 \pm 0.09 rad m$^{-2}$, respectively. The linear polarization distributions among five repeating FRB--FRBs~20190208A, 20190303A, 20201124A, 20220912A, and 20240114A--are nearly identical but show distinct differences from those of non-repeating FRBs. FRBs~20190117A, 20190303A, and 20190417A exhibit substantial rotation measure (RM) variations between bursts, joining other repeating FRBs in this behavior. Combining these findings with published results, 64% of repeating FRBs show RM variations greater than 50 rad m$^{-2}$, and 21\% exhibit RM reversals. A significant proportion of repeating FRBs reside in a dynamic magneto-ionic environment. The structure function of RM variations shows a power-law index of $γ\sim (0-0.8)$, corresponding to a shallow power spectrum $α= -(γ+ 2) \sim -(2.0-2.8)$ of turbulence, if the RM variations are attributed to turbulence. This suggests that the variations are dominated by small-scale RM density fluctuations. We perform K-S tests comparing the RMs of repeating and non-repeating FRBs, which reveal a marginal dichotomy in the distribution of their RMs.We caution that the observed dichotomy may be due to the small sample size and selection biases.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02355
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Multi-year Polarimetric Monitoring of Four CHIME-Discovered Repeating Fast Radio Bursts with FAST
Feng, Yi
Zhang, Yong-Kun
Xie, Jintao
Yang, Yuan-Pei
Qu, Yuanhong
Zhou, Dengke
Li, Di
Zhang, Bing
Zhu, Weiwei
Lu, Wenbin
Xu, Jiaying
Miao, Chenchen
Tian, Shiyan
Wang, Pei
Yao, Ju-Mei
Niu, Chen-Hui
Niu, Jiarui
Xu, Heng
Jiang, Jinchen
Zhou, Dejiang
Liu, Zenan
Tsai, Chao-Wei
Dai, Zigao
Wu, Xuefeng
Wang, Fayin
Han, Jinlin
Lee, Kejia
Xu, Renxin
Huang, Yongfeng
Zou, Yuanchuan
Cao, Jinhuang
Chen, Xianglei
Fang, Jianhua
Li, Dongzi
Li, Ye
Lu, Wanjin
Luo, Jiawei
Luo, Jintao
Luo, Rui
Lyu, Fen
Wang, Bojun
Wang, Weiyang
Wu, Qin
Xue, Mengyao
Xiao, Di
Yu, Wenfei
Yuan, Jianping
Zhang, Chunfeng
Zhang, Junshuo
Zhang, Lei
Zhang, Songbo
Zhao, Rushuang
Zhu, Yuhao
High Energy Astrophysical Phenomena
In this study, we report multi-year polarization measurements of four repeating FRBs initially discovered by CHIME: FRBs~20190117A, 20190208A, 20190303A, and 20190417A. We observed the four repeating FRBs with FAST, detecting a total of 66 bursts. Two bursts from FRB~20190417A exhibit a circular polarization signal-to-noise ratio greater than 7, with the highest circular polarization fraction recorded at 35.7%. While the bursts from FRBs 20190208A and 20190303A are highly linearly polarized, those from FRBs~20190117A and 20190417A show depolarization due to multi-path propagation, with σ_{\mathrm{RM}} = 2.78 \pm 0.05 rad m$^{-2}$ and 5.19 \pm 0.09 rad m$^{-2}$, respectively. The linear polarization distributions among five repeating FRB--FRBs~20190208A, 20190303A, 20201124A, 20220912A, and 20240114A--are nearly identical but show distinct differences from those of non-repeating FRBs. FRBs~20190117A, 20190303A, and 20190417A exhibit substantial rotation measure (RM) variations between bursts, joining other repeating FRBs in this behavior. Combining these findings with published results, 64% of repeating FRBs show RM variations greater than 50 rad m$^{-2}$, and 21\% exhibit RM reversals. A significant proportion of repeating FRBs reside in a dynamic magneto-ionic environment. The structure function of RM variations shows a power-law index of $γ\sim (0-0.8)$, corresponding to a shallow power spectrum $α= -(γ+ 2) \sim -(2.0-2.8)$ of turbulence, if the RM variations are attributed to turbulence. This suggests that the variations are dominated by small-scale RM density fluctuations. We perform K-S tests comparing the RMs of repeating and non-repeating FRBs, which reveal a marginal dichotomy in the distribution of their RMs.We caution that the observed dichotomy may be due to the small sample size and selection biases.
title Multi-year Polarimetric Monitoring of Four CHIME-Discovered Repeating Fast Radio Bursts with FAST
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2507.02355