近日，加拿大麦吉尔大学的Ryan Mckinven及其研究团队取得一项新进展。他们观测到附近快速射电暴产生的类似脉冲星的极化角摆动。相关研究成果已于2025年1月1日在国际权威学术期刊《自然》上发表。

该研究团队报道了由加拿大氢强度测绘实验快速射电暴项目（CHIME/FRB）探测到的FRB 20221022A，其定位在附近的一个宿主星系MCG+14-02-011（距离约65百万秒差距）。该FRB在其约2.5毫秒的持续时间内，显示出显著的约130°的线性极化位置角（PA）旋转，类似于许多脉冲星和一些射电磁星中观察到的特征性S形演变。

观测到的PA演变支持磁层起源，而非涉及远距离激波的模型，这与对一些重复FRB的时间-偏振研究所得出的结论相呼应。PA演变很好地符合旋转矢量模型（RVM）的描述，尽管由于源的周期或占空比未知，研究人员无法确定其倾角和磁斜角，但可以排除极短周期脉冲星（例如，再生毫秒脉冲星）作为其前身。

据悉，快速射电暴（FRB）持续时间仅为毫秒级，却能从宇宙学距离遥远的地方抵达地球。尽管它们的起源和发射机制尚不清楚，但它们的信号与银河系内脉冲星产生的亮度低得多的射电辐射存在相似之处，某些特性暗示它们可能源自中子星。然而，与脉冲星不同的是，FRB的线性极化位置角（PA）曲线通常变化极小。即使当PA曲线出现明显变化时，它们也显著偏离脉冲星旋转矢量模型（RVM）所预测的典型形状。

附：英文原文

Title: A pulsar-like polarization angle swing from a nearby fast radio burst

Author: Mckinven, Ryan, Bhardwaj, Mohit, Eftekhari, Tarraneh, Kilpatrick, Charles D., Kirichenko, Aida, Pal, Arpan, Cook, Amanda M., Gaensler, B. M., Giri, Utkarsh, Kaspi, Victoria M., Michilli, Daniele, Nimmo, Kenzie, Pearlman, Aaron B., Pleunis, Ziggy, Sand, Ketan R., Stairs, Ingrid, Andersen, Bridget C., Andrew, Shion, Bandura, Kevin, Brar, Charanjot, Cassanelli, Tomas, Chatterjee, Shami, Curtin, Alice P., Dong, Fengqiu Adam, Eadie, Gwendolyn, Fonseca, Emmanuel, Ibik, Adaeze L., Kaczmarek, Jane F., Kharel, Bikash, Lazda, Mattias, Leung, Calvin, Li, Dongzi, Main, Robert, Masui, Kiyoshi W., Mena-Parra, Juan, Ng, Cherry, Pandhi, Ayush, Patil, Swarali Shivraj, Prochaska, J. Xavier, Rafiei-Ravandi, Masoud, Scholz, Paul, Shah, Vishwangi, Shin, Kaitlyn, Smith, Kendrick

Issue&Volume: 2025-01-01

Abstract: Fast radio bursts (FRBs) last for milliseconds and arrive at Earth from cosmological distances. Although their origins and emission mechanisms are unknown, their signals bear similarities with the much less luminous radio emission generated by pulsars within our Miky Way Galaxy, with properties suggesting neutron star origins. However, unlike pulsars, FRBs typically show minimal variability in their linear polarization position angle (PA) curves. Even when marked PA evolution is present, their curves deviate significantly from the canonical shape predicted by the rotating vector model (RVM) of pulsars. Here we report on FRB 20221022A, detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst project (CHIME/FRB) and localized to a nearby host galaxy (about 65Mpc), MCG+14-02-011. This FRB shows a notable approximately 130° PA rotation over its about 2.5ms burst duration, resembling the characteristic S-shaped evolution seen in many pulsars and some radio magnetars. The observed PA evolution supports magnetospheric origins over models involving distant shocks, echoing similar conclusions drawn from tempo-polarimetric studies of some repeating FRBs. The PA evolution is well described by the RVM and, although we cannot determine the inclination and magnetic obliquity because of the unknown period or duty cycle of the source, we exclude very short-period pulsars (for example, recycled millisecond pulsars) as the progenitor.

DOI: 10.1038/s41586-024-08184-4

Source: https://www.nature.com/articles/s41586-024-08184-4