Parkes observations for project P1338 semester 2025APRS_49

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, FRBs）是一类起源于河外的毫秒级时长射电暴。自首次在帕克斯/穆里扬（Parkes/Murriyang）多波束存档数据中发现第一例FRB以来，该类暴源的种群已呈现出清晰的二分特征：尽管已通过多台不同射电望远镜开展了大量后续观测，但部分FRB被观测到存在重复爆发行为，而另一部分则无重复爆发现象。

近期由CHIME/FRB发现的重复暴FRB 20240114A，展现出异常高的爆发活动频率，此类极端爆发活动在其他任何暴源中均未被观测到。

重复FRB（如FRB 20240114A）凭借其重复爆发的特性，为研究其暴周环境提供了无与伦比的观测窗口，可用于约束潜在的前身星模型并验证核心辐射机制。

此前针对帕克斯/穆里扬望远镜探测到的暴源开展的后续观测，还揭示了诸多有趣的光谱偏振特性，例如爆发中心频率的频率依赖演化或色特性、疑似存在的活动窗口、显著大振幅的圆偏振（Circular Polarisation, CP）以及频率依赖的圆偏振。这些特性是理解FRB暴周环境、验证各类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，是揭示此类特性的关键支撑。

帕克斯/穆里扬望远镜搭载的超宽带低（Ultra-Wideband Low, UWL）接收机，恰好能够完美适配该暴源的宽带光谱时域与偏振特性研究。

我们提议开展一项定期观测计划，对FRB 20240114A进行持续后续观测，以明确其光谱时域特性的长期演化规律。