Parkes observations for project P1338 semester 2025APRS_12

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射电爆发。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，该爆发源群体便呈现出显著的二分特性：尽管后续利用不同射电望远镜开展了大量观测，但部分FRB被证实可重复爆发，另一部分则无重复信号。近期由加拿大氢强度测绘实验/快速射电暴巡天（CHIME/FRB）发现的重复暴FRB 20240114A，展现出极高的爆发活动率，这一极端活跃的特性在其他任何FRB源中均未被观测到。这类可重复爆发的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。此前对帕克斯/穆里扬望远镜观测源的后续研究，还揭示了一系列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（或称色特性）、潜在的活动窗口、显著大振幅的圆偏振（Circular Polarisation, CP）以及频率依赖的圆偏振。这些特性是破解FRB暴周环境、验证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，是揭示上述特性的核心条件。帕克斯/穆里扬望远镜搭载的超低频宽带（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。本观测计划拟对FRB 20240114A开展常态化后续观测，以明确其光谱时域特性的长期演化规律。