Parkes observations for project P1183 semester 2024OCTS_13

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.经过近两年的监测工作，我们依托帕克斯望远镜（Parkes telescope）完成57次观测、累计有效时长126.7小时，同时使用FAST望远镜开展101次观测、累计时长49.4小时，由此确认FRB 20220529是一颗活跃度极高的重复快速射电暴。该暴源的活动持续时长位居已知同类暴源前列，且存在潜在的周期信号。得益于针对帕克斯望远镜与FAST望远镜的密集观测计划，我们近期在该源中探测到一次突变的旋转量（rotation measure, RM）耀发现象——这是快速射电暴（fast radio burst, FRB）领域内此类‘RM耀发’的首次观测报道，暗示该源所处的环境中存在偶发的日冕物质抛射活动。这为研究快速射电暴的爆发环境提供了独一无二的研究契机，同时可用于探究暴源活动与其他暴参数之间的内在关联。若该周期性与‘RM耀发’均得到进一步证实，二者将互为佐证，成为快速射电暴双星起源假说的决定性证据。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望远镜凭借更高的灵敏度成功捕获了大量暴源信号，而帕克斯望远镜的宽频接收机即便在暴源活动率较低的阶段，仍能保持优异的暴源探测效率。尤为关键的是，在RM耀发期间，帕克斯望远镜获取的两例高信噪比（signal-to-noise ratio）暴源信号，为我们理解旋转量的变化机制提供了核心支撑。为进一步深入研究FRB 20220529，我们已规划每两周开展一次FAST常规观测，每次对该源进行20分钟的持续监测。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，以保障高时间分辨率，并采用全偏振观测（full-polarization observations）方案。