Ninety percent circular polarization detected in a repeating fast radio burst  

作　　者：Jinchen Jiang Jiangwei Xu Jiarui Niu Kejia Lee Weiwei Zhu Bing Zhang Yuanhong Qu Heng Xu Dejiang Zhou Shunshun Cao Weiyang Wang Bojun Wang Shuo Cao Yongkun Zhang Chunfeng Zhang Hengqian Gan Jinlin Han Longfei Hao Yuxiang Huang Peng Jiang Dongzi Li Hui Li Ye Li Zhixuan Li Rui Luo Yunpeng Men Lei Qian Jinghai Sun Lin Wang Yonghua Xu Renxin Xu Yuanpei Yang Rui Yao Youling Yue Dongjun Yu Jianping Yuan Yan Zhu 

机构地区：[1]National Astronomical Observatories,Chinese Academy of Sciences(CAS),Beijing 100101,China [2]Department of Astronomy,Peking University,Beijing 100871,China [3]Kavli Institute for Astronomy and Astrophysics,Peking University,Beijing 100871,China [4]Beijing Laser Acceleration Innovation Center,Peking University,Beijing 101400,China [5]Nevada Center for Astrophysics,University of Nevada,Las Vegas 89154,USA [6]Department of Physics and Astronomy,University of Nevada,Las Vegas 89154,USA [7]School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China [8]Yunnan Observatories,CAS,Kunming 650216,China [9]Department of Astrophysical Sciences,Princeton University,Princeton 08544,USA [10]Purple Mountain Observatory,CAS,Nanjing 210008,China [11]School of Physics and Electronic Engineering,Guangzhou University,Guangzhou 510006,China [12]Electronic Department,Max-Planck institut für Radioastronomie,Bonn 53121,Germany [13]South-Western Institute For Astronomy Research,Yunnan University,Kunming 650504,China [14]State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China [15]Xinjiang Astronomical Observatory,CAS,Urumqi 830011,China

出　　处：《National Science Review》2025年第2期29-35,共7页国家科学评论(英文版)

基　　金：supported by the National SKA Program of China(2020SKA0120100,2020SKA0120200);the National Natu-ral Science Foundation of China(12041304,11873067,11988101,12041303,11725313,11725314,11833003,12003028,12041306,12103089,U2031209,U2038105,U1831207);funding from the Max-Planck Partner Group and support from the XPLORER PRIZE.

摘　　要：Fast radio bursts(FRBs)are extra-galactic sources with unknown physical mechanisms.They emit mi l lisecond-duration radio pulses with isotropic equivalent energy of 10^(36)-10^(41) ergs.This corresponds to a brightness temperature of FRB emission typically reaching the level of 10^(36) K,but can be as high as above 10^(40) Kforsub-microsecond timescale structures,suggesting the presence of underlying coherent relativistic radiation mechanisms.Polarization carries key information to understand the physical origin of FRBs,with linear polarization usually tracing the geometric configuration of magnetic fields and circular polarization probing both intrinsic radiation mechanisms and propagation effects.Here we show that the repeating source FRB 20201124A emits 90.9%±1.1%circularly polarized radio pulses.Such a high degree of circular polarization was unexpected in theory and unprecedented in observation in the case of FRBs,since such a high degree of circular polarization was only common among solar or Jovian radio activities,attributed to the sub-relativistic electrons.We note that there is no obvious correlation between the degree of circular polarization and burst fluence.Besides the high degree of circular polarization,we also detected a rapid swing and orthogonal jump in the position angle of linear polarization.The detection of high-degree circular polarization in FRB 20201124A,together with its linear polarization properties that show orthogonal modes,place strong constraints on FRB physical mechanisms,calling for an interplay between magnetospheric radiation and propagation effects in shaping the observed FRB radiation.

关 键 词：radio astronomy fast radio burst POLARIZATION 

分 类 号：TN9[电子电信—信息与通信工程]