Parkes observations for project P1338 semester 2024OCTS_11

Fast radio bursts (FRBs) are millisecond-duration radio bursts of extragalactic origin. Since the discovery of the first FRB in the archival Parkes/Murriyang multibeam data, a broad dichotomy in population has emerged. Some FRBs have been seen to be repeating, while others are not, despite a significant amount of follow-up using different radio telescopes. The repeating FRB 20240114A was recently discovered by CHIME/FRB, which has been seen to have an exceptionally high burst activity. Such extreme burst activity has not been seen in any other source. The repeating FRBs, such as FRB 20240114A, provide an unparalleled window into their circumburst environment due to their repeating nature, which can be used to constrain possible progenitor models and test underlying emission mechanisms. The previous Parkes/Murriyang source follow-up has also revealed intriguing spectro-polarimetric properties, such as frequency-dependent evolution of burst central frequency or chromaticity, a possible activity window, significantly large circular polarisation (CP), and frequency-dependent CP. These properties hold the key towards understanding the circumburst environment of the FRBs, and test possible progenitor models. A large bandwidth instrument with reliable polarimetry has been critical in uncovering these properties. The ultra-wideband low (UWL) receiver on Parkes/Murriyang is ideally suited to explore the source's wideband spectro-temporal and polarimetric behaviour. We propose a campaign to regularly follow up FRB 20240114A to ascertain its long-term evolution of spectro-temporal properties.

快速射电暴（Fast radio bursts）是起源于河外的毫秒级持续时间射电暴。自从在Parkes/Murriyang多波束存档数据中发现首个FRB以来，其种群已呈现出明显的二分性。部分FRB被观测到具有重复爆发特性，而另一些则没有，尽管使用不同射电望远镜进行了大量后续观测。重复爆发的FRB 20240114A最近由CHIME/FRB发现，其爆发活动异常频繁，这种极端爆发活动在其他任何源中均未观测到。像FRB 20240114A这样的重复FRB，因其重复特性为研究其爆发周围环境提供了独一无二的窗口，可用于限制可能的前身星模型并检验潜在的辐射机制。此前对Parkes/Murriyang源的后续观测还揭示了引人关注的光谱偏振特性，例如爆发中心频率随频率变化的演化或色性、可能存在的活动窗口、显著的圆偏振（circular polarisation）以及频率相关的CP。这些特性是理解FRB爆发周围环境及检验可能前身星模型的关键。具备可靠偏振测量能力的大带宽仪器对于揭示这些特性至关重要。Parkes/Murriyang上的超宽带低频（ultra-wideband low）接收器非常适合探索该源的宽带光谱时间和偏振行为。我们提议开展一项定期后续观测FRB 20240114A的计划，以确定其光谱时间特性的长期演化。