Parkes observations for project P1338 semester 2025APRS_44

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射电爆发。自存档的帕克斯/穆里扬（Parkes/Murriyang）多波束观测数据中发现首例快速射电暴以来，其爆发群体便呈现出鲜明的二分特征：尽管学界已利用各类射电望远镜开展了大量后续观测，但部分快速射电暴会重复爆发，而另一部分则仅出现单次爆发。重复暴FRB 20240114A近日由CHIME/FRB项目发现，其爆发活动率异常之高，此类极端爆发活动在其他任何射电暴源中均未被观测到。诸如FRB 20240114A这类重复快速射电暴，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）望远镜观测源的后续观测，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）以及与频率相关的圆偏振。这些特性是破解快速射电暴暴周环境、验证各类潜在前身星模型的关键。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工具。帕克斯/穆里扬（Parkes/Murriyang）望远镜搭载的超宽带低（Ultra-wideband Low, UWL）接收机，恰好可用于探究该暴源的宽频光谱时域与偏振特性。我们提议开展一项针对FRB 20240114A的常态化后续观测计划，以厘清其光谱时域特性的长期演化规律。