Parkes observations for project P1338 semester 2024OCTS_09

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，其爆发群体已呈现出清晰的二分特征：尽管利用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，另一部分则无重复爆发。
重复暴FRB 20240114A近期由CHIME/FRB项目发现，该暴展现出异常高的爆发活动率，此类极端爆发活动此前从未在其他源中被观测到。
得益于重复爆发的特性，此类重复FRB（如FRB 20240114A）为研究其爆发周围环境提供了独一无二的窗口，可用于约束可能的前身星模型并检验其核心辐射机制。
此前针对帕克斯/穆里扬望远镜观测源的后续研究还揭示了引人关注的光谱偏振特性，例如爆发中心频率的频率依赖演化（或称色偏现象）、可能存在的活动窗口、显著较大的圆偏振（Circular Polarisation, CP）以及圆偏振的频率依赖行为。这些特性是理解FRB爆发周围环境、检验各类前身星模型的关键。
具备可靠偏振测量能力的大带宽仪器，是揭示这些特性的核心关键。帕克斯/穆里扬望远镜上的超宽带低频（Ultra-Wideband Low, UWL）接收机，非常适合用于探究该源的宽频光谱时域与偏振行为。
我们提议开展一项定期跟进观测FRB 20240114A的观测计划，以明确其光谱时域特性的长期演化规律。