Parkes observations for project P1338 semester 2024OCTS_54

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）是起源于河外星系的毫秒级持续射电暴。自首次在存档的帕克斯/穆里扬（Parkes/Murriyang）多波束观测数据中发现第一例FRB以来，该类天体的种群便呈现出显著的二分特性：尽管学界已借助多台不同射电望远镜开展了大量后续观测，但部分FRB被观测到具有重复爆发特性，其余则无重复爆发行为。重复爆发快速射电暴20240114A近期由CHIME/FRB项目发现，该源展现出异常高的爆发活跃度，这类极端的爆发活跃度在其他任何射电源中均未被观测到。重复爆发快速射电暴（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可比拟的窗口，可用于约束潜在的前身星模型并检验核心辐射机制。此前针对帕克斯/穆里扬（Parkes/Murriyang）观测源的后续研究还揭示了诸多引人关注的光谱偏振特性，例如爆发中心频率的频率依赖性演化（即色特性）、潜在的活跃窗口、显著的高圆偏振度（CP）以及圆偏振的频率依赖性。这些特性是破解FRB暴周环境、验证各类潜在前身星模型的关键所在。具备可靠偏振测量能力的大带宽观测设备，是揭示上述特性的关键工具。帕克斯/穆里扬（Parkes/Murriyang）搭载的超宽带低频（UWL）接收机，非常适合用于研究该源的宽频带光谱时域与偏振特性。我们提议开展一项针对FRB 20240114A的定期后续观测计划，以明确其光谱时域特性的长期演化规律。