Parkes observations for project P1338 semester 2025APRS_17

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）是一类起源于河外空间、持续时长仅为数毫秒的射电暴。自首次在帕克斯（Parkes）/穆里扬（Murriyang）多波束存档数据中发现第一例快速射电暴以来，该类天体的种群便呈现出显著的二分特征。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，但部分快速射电暴被证实存在重复爆发现象，另一部分则无重复爆发特征。近期由CHIME/FRB项目发现的重复爆发型快速射电暴FRB 20240114A，展现出异常高的爆发活动率。迄今尚未在其他任何天体中观测到如此极端的爆发活动。诸如FRB 20240114A这类重复爆发型快速射电暴，凭借其重复爆发的特性，为研究其暴周环境提供了独一无二的观测窗口，可用于约束潜在的前身天体模型并检验核心辐射机制。此前针对帕克斯/穆里扬望远镜观测源的后续研究，还揭示了诸多引人关注的光谱偏振特性：例如暴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、极强的圆偏振（Circular Polarisation，CP）信号，以及圆偏振的频率依赖行为。这些特性是解析快速射电暴暴周环境、验证各类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关键。帕克斯/穆里扬望远镜搭载的超低频宽带（Ultra-Wideband Low，UWL）接收机，恰好能够完美适配该源的宽带光谱时域与偏振特性研究。本研究提议开展针对FRB 20240114A的常态化后续观测计划，以明确其光谱时域特性的长期演化规律。