Paper

FAST Polarization Catalog of FRB 20240114A

Long-Xuan, Zhang, Chen, Xuelei, Qing-Yue Qu, Zou, Yuan-Chuan, Chen-Chen, Miao, Yi-Dan, Wang, Feng, Shuai, Xiao-Hui, Liu, Yong-Feng, Huang, Xiang-Han, Cui, Su-Ming, Weng, Yong-Kun, Zhang, Chun-Feng, Zhang, Feng, Yi, Jin-Huang, Cao, Jia-Wei, Luo, Zhang, Bing, Shi-Yan, Tian, Yuan-Hong, Qu, Bo-Jun, Wang, Dong-Zi, Li, Tian-Cong, Wang, Zhang, Lei, Jia-Rui Niu, Wei-Wei, Zhu, Li, Ye, Zhao, Ru-Shuang, De-Jiang, Zhou, Chao-Wei, Tsai, Luo, Rui, Zhang, Jun-Shuo, Li, Di, Cao, Shuo, Yu-Hao, Zhu, Ke-Jia, Lee, Fang, Jianhua, Yuan-Pei, Yang, Xie, Jintao, Zi-Wei, Wu, Ai-Yuan, Yang, Wei-Cong, Jing, Si-Lu, Xu, Fa-Yin Wang, Lin, Lin, Wen-Fei, Yu, Chen-Hui, Niu, Gao, He, Xiao-Feng, Cheng, Gugercinoglu, E, Li, Jian, Zhou, Dengke, Chen, Yunchuan, Wu, Qin, Wan-Jin, Lu, Chen, Huaxi, Shi-Han, Yew, Wei-Yang, Wang, Xiang-Lei, Chen, Jin-Lin, Han, Yu-Xiang, Huang, Xue-Feng, Wu, Wang, Pei, Xu, Heng

2026

Overview

Polarization measurements of fast radio bursts (FRBs) probe the magnetized plasma surrounding their central engines. FRB~20240114A is an exceptionally active repeating source, with 17,356 bursts detected between 2024 January 28 and 2025 May 30 by FAST, enabling time-resolved polarimetric studies. In this work, we present a polarimetric catalog of 6,131 bright bursts (with a signal-to-noise ratio S/N \\(\\) 20, 35.3% of the total sample), including arrival time (MJD\\(_topo\\)), dispersion measure (DM), burst width (W\\(_eff\\)), bandwidth, Faraday rotation measure (RM), linear and circular polarization degrees (DOL, DOC), and intrinsic polarization angle (PA\\(_0\\)). We detect a clear temporal evolution of RM: after an initial stable phase, it decreases linearly by \\(\\)200 \\( rad\\ m^-2\\) over 200 days, forming a bimodal distribution, whereas DM remains stable at 528.9 \\( pc\\ cm^-3\\). The linear polarization fraction is generally high, with the 3\\(\\) lower bound around 76%, while circular polarization is low, with 1,157 of 17,356 bursts (6.67%) having DOC \\(\\)10%. We perform a power-law fit between \\(|V|\\)/I and \\(|RM|\\), which yields an index of \\(-2.98 0.80\\). It is found that the combined 2D distribution of L/I versus V/I remains stable, implying that the emission mechanism is largely invariant. Our PA\\(_0\\) measurements show a broad, non-uniform distribution, implying a complex emission geometry. These results suggest that FRB~20240114A resides in a dynamically evolving magneto-ionic environment. This catalog provides a foundation for studies of repeating FRB progenitors and their environments.

• Publisher: Cornell University Library, arXiv.org
• Subject: Circular polarization / Emission / Faraday effect / Linear polarization / Lower bounds / Polarimetry / Radio bursts / Signal to noise ratio