Parkes observations for project P1068 semester 2021APRS_08

In the fast-moving world of Fast Radio Bursts (FRBs), the critical question of what fraction of FRBs emit repeat bursts remains unanswered. Of order 20 repeating FRBs are now known, and their spectro-temporal properties hint at differences with apparently non-repeating bursts - the poor statistics preclude a definitive diagnosis. FRB 180301 is a promising source for further study for multiple reasons: it is an active repeater similar to the FRB 121102 and the most active FRB source visible to Parkes, and it shows diverse polarization properties across the repeat bursts. We have detected multiple repeat bursts from this source in our campaign last semester. The signal-to-noise ratio (S/N) of these detections are not sufficiently significant to measure their spectro-polarimetric properties. We request Parkes observations with the UWL receiver to continue the monitoring of this FRB source in order to characterize the broadband emission properties. Some of the key goals for these future observations are: to constrain the repetition rate, identify any variation of pulse characteristics over time, measure the polarimetric properties and provide insight into the emission mechanisms. The diverse polarization angle swings in the FAST detections and significant circular polarization in the original Parkes detection indicate the progenitor is embedded in an extreme magneto-ionic environment with complex field structure that has not been seen before. Understanding these diverse polarization properties from this source could be the key to distinguish repeater sources from the apparent non-repeaters ones.

在快速射电暴（Fast Radio Bursts, FRBs）这一发展迅速的领域中，核心问题——即FRBs中有多大比例会发射重复暴——仍未得到解答。目前已知约20个重复型FRBs，其光谱-时间特性暗示它们与明显的非重复型暴存在差异，但统计数据不足使得无法得出明确结论。FRB 180301是一个值得深入研究的潜在源，原因有多个：它是一个活跃的重复型暴，与FRB 121102相似，且是Parkes望远镜可观测到的最活跃FRB源；此外，其重复暴展现出多样的偏振特性。我们在上学期的观测活动中检测到该源的多个重复暴。这些探测结果的信噪比（signal-to-noise ratio, S/N）不够显著，无法测量其光谱偏振特性。我们申请使用Parkes望远镜的UWL接收器进行观测，以持续监测该FRB源，从而表征其宽带发射特性。这些未来观测的关键目标包括：约束重复率、识别脉冲特性随时间的变化、测量偏振特性，以及深入了解发射机制。FAST探测中观测到的多样偏振角摆动，以及原始Parkes探测中显著的圆偏振，表明其前身星嵌入在一个前所未见的极端磁离子环境中，该环境具有复杂的场结构。理解该源的这些多样偏振特性，可能是区分重复型源与明显非重复型源的关键。