Parkes observations for project P1338 semester 2025APRS_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持续射电爆发现象。自帕克斯/穆里扬射电望远镜的多波束存档数据中发现首例FRB以来，其天体群体已呈现出显著的二分特性：部分FRB表现出重复爆发行为，而另一些则无重复爆发迹象，尽管学界已利用多台不同射电望远镜开展了大量后续观测。重复暴FRB 20240114A近期由CHIME/FRB项目组发现，该暴展现出异常高的爆发活跃度，这种极端爆发特性在其他任何射电暴源中均未被观测到。重复爆发的FRB（如FRB 20240114A）凭借其重复爆发的固有特性，为研究其爆发周围环境提供了独一无二的窗口，可用于约束潜在的前身天体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）、潜在的爆发活动窗口、显著的高圆偏振（circular polarisation, CP）以及频率依赖的圆偏振。这些特性是解析FRB爆发周围环境、验证潜在前身天体模型的关键所在。具备可靠偏振测量能力的大带宽观测设备，是揭示上述特性的核心前提。帕克斯/穆里扬射电望远镜搭载的超宽带低频（ultra-wideband low, UWL）接收机，恰好能够完美适配该源的宽带频谱-时域与偏振特性研究。本研究提议开展针对FRB 20240114A的常态化后续观测，以明确其频谱-时域特性的长期演化规律。