We present the scintillation velocity measurements of FRB 20201124A from the Five-hundred-meter Aperture Spherical radio Telescope observations, which reveal an annual variation. This annual variation is further supported by changes detected in the scintillation arc as observed from the secondary spectrum. We attribute the annual velocity variation to the presence of a moderately anisotropic scattering screen located at a distance of 0.4 ± 0.1 kpc from Earth. Our results prove that the scintillation of this fast radio burst (FRB) is mainly caused by material close to Earth on a Galactic scale. However, scintillation observations of other FRBs may expose their surrounding environment or uncover possible orbital motion if scintillation is caused by materials in their host galaxy.

中文翻译：

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FRB 20201124A 的闪烁速度和电弧观测


我们展示了来自 500 米孔径球面射电望远镜观测的 FRB 20201124A 闪烁速度测量结果，揭示了年度变化。从二次光谱中观察到的闪烁弧中检测到的变化进一步支持了这种年度变化。我们将年速度变化归因于距地球 0.4 ± 0.1 kpc 处存在中等各向异性散射屏。我们的结果证明，这种快速射电暴（FRB）的闪烁主要是由银河尺度上靠近地球的物质引起的。然而，如果闪烁是由其宿主星系中的物质引起的，对其他快速射电暴的闪烁观测可能会暴露其周围环境或揭示可能的轨道运动。