Parkes observations for project P1183 semester 2024OCTS_08

After nearly two years of monitoring, comprising 126.7 hours over 57 observations with the Parkes telescope and 49.4 hours across 101 observations with the FAST telescopes, we have determined that FRB 20220529 is an extremely active repeater. It exhibits one of the longest activity durations and a potential period. Due to frequent observations scheduled with both Parkes and FAST, we recently observed an abrupt rotation measure (RM) flare in this source. This is the first detection of such an ``RM flare'' in a fast radio burst (FRB), suggesting that the source is in an environment with occasionally erupting coronal mass ejection. This presents a unique opportunity to study the eruption environment of FRBs and investigate the relation between burst activity and other burst parameters. If confirmed, the periodicity and the ``RM flare'' of FRB 20220529 would corroborate each other and become a ``smoking gun'' of the binary origin of FRB. In our previous analysis, both Parkes and FAST observations have proven essential. While FAST's higher sensitivity has enabled the capture of many bursts, Parkes' wideband receiver has provided a good burst detection rate even during low-rate phases. Notably, during the RM flare, two high signal-to-noise ratio bursts from Parkes have been crucial in understanding the RM variations. To further investigate FRB 20220529, we have scheduled regular FAST observations every fortnight, monitoring the source for 20 minutes each time. Therefore, we also propose to monitor FRB 20220529 using the Parkes UWL receiver, ensuring high-time resolution and employing full-polarization observations.

历经近2年的监测工作：依托帕克斯望远镜（Parkes telescope）完成57次观测、累计时长126.7小时，依托FAST望远镜完成101次观测、累计时长49.4小时，我们确认FRB 20220529是一颗极度活跃的重复快速射电暴（fast radio burst, FRB）。该源是目前已知活动持续时长最长的源之一，且展现出潜在的周期性。鉴于我们针对帕克斯望远镜与FAST望远镜均安排了高频观测计划，近期我们在该源中观测到一次突发性的旋转测量量（rotation measure, RM）耀变事件。这是人类首次在快速射电暴（FRB）中观测到此类“RM耀变”现象，暗示该源所处环境中存在偶发的日冕物质抛射（coronal mass ejection）活动。这为研究快速射电暴的爆发环境提供了独一无二的契机，同时可用于探究爆发活动与其他爆发参数之间的内在关联。若该源的周期性与“RM耀变”现象均得到证实，二者将互为佐证，成为快速射电暴双星起源的“确凿证据（smoking gun）”。在我们此前的分析工作中，帕克斯望远镜与FAST望远镜的观测数据均发挥了不可或缺的作用。FAST凭借更高的灵敏度捕捉到了大量爆发事件，而帕克斯望远镜的宽带接收机即便在爆发率较低的阶段，也能保持优异的爆发探测效率。值得注意的是，在此次RM耀变期间，帕克斯望远镜观测到的两例高信噪比爆发事件，对我们理解旋转测量量的变化起到了关键支撑作用。为进一步研究FRB 20220529，我们已计划每两周开展一次FAST常规观测，每次对该源进行20分钟的监测。据此，我们同时提议使用帕克斯望远镜的UWL接收机对FRB 20220529开展监测，采用全极化观测模式以保障高时间分辨率。