Parkes observations for project P1183 semester 2024OCTS_15

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.

经过近两年的监测，我们利用帕克斯望远镜（Parkes telescope）完成了57次观测、累计时长126.7小时，同时借助FAST望远镜开展了101次观测、累计时长49.4小时，由此确定快速射电暴（Fast Radio Burst, FRB）20220529是一颗活跃度极高的重复暴。该源具备目前已知最长的活动持续时长之一，并呈现出潜在的周期特征。得益于我们针对帕克斯望远镜与FAST望远镜均安排的高频观测计划，我们近期在该源中探测到了一次突发性的旋转测量（Rotation Measure, RM）耀发。这是快速射电暴领域首次观测到此类"RM耀发"现象，表明该源所处的环境中存在偶发的日冕物质抛射（coronal mass ejection）活动。这一发现为研究快速射电暴的爆发环境、探究暴活动与其他暴参数之间的关联提供了独一无二的契机。若后续得到验证，FRB 20220529的周期性特征与"RM耀发"将互为佐证，成为快速射电暴双星起源的确凿证据。在我们此前的分析中，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望远镜凭借更高的灵敏度捕捉到了大量暴信号，而帕克斯望远镜的宽频接收机即便在暴活动率较低的阶段，也能保持优异的暴探测效率。值得注意的是，在此次RM耀发期间，帕克斯望远镜观测到的两例高信噪比（signal-to-noise ratio）暴信号，对我们理解RM的变化机制起到了关键作用。为进一步开展对FRB 20220529的研究，我们已计划每双周开展一次FAST望远镜常规观测，每次对该源进行20分钟的监测。此外，我们还提议利用帕克斯望远镜的UWL接收机对FRB 20220529开展监测，采用全偏振观测模式以保障高时间分辨率的数据采集。