Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, China.
National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China.
Nature. 2020 Oct;586(7831):693-696. doi: 10.1038/s41586-020-2827-2. Epub 2020 Oct 28.
Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown origin. Two possible mechanisms that could generate extremely coherent emission from FRBs invoke neutron star magnetospheres or relativistic shocks far from the central energy source. Detailed polarization observations may help us to understand the emission mechanism. However, the available FRB polarization data have been perplexing, because they show a host of polarimetric properties, including either a constant polarization angle during each burst for some repeaters or variable polarization angles in some other apparently one-off events. Here we report observations of 15 bursts from FRB 180301 and find various polarization angle swings in seven of them. The diversity of the polarization angle features of these bursts is consistent with a magnetospheric origin of the radio emission, and disfavours the radiation models invoking relativistic shocks.
快速射电暴（FRB）是一种持续时间为毫秒级的未知起源的射电瞬变现象。有两种可能的机制可以产生来自 FRB 的极相干发射，一种是利用中子星磁层，另一种是利用远离中心能源的相对论激波。详细的偏振观测可能有助于我们理解发射机制。然而，现有的 FRB 偏振数据令人困惑，因为它们显示出许多偏振特性，包括一些重复源在每个爆发期间的偏振角保持不变，或者在一些其他明显的单次事件中偏振角变化。在这里，我们报告了对 FRB 180301 的 15 次爆发的观测结果，发现其中 7 次存在各种偏振角摆动。这些爆发的偏振角特征的多样性与射电辐射的磁层起源一致，不支持涉及相对论激波的辐射模型。
