Parkes observations for project P1172 semester 2022OCTS_11

PSR J1713+0747 is an extremely stable millisecond pulsar used in global pulsar timing array campaigns as a high priority pulsar because of its strong S/N, narrow profile and long-term observation history. In April 2021, the pulsar experienced a significant event related to a change in its magnetosphere, presented as an observable change in the pulsar’s profile. Since then, the pulsar has been slowly recovering and we wish to observe it with high cadence to allow us to create a detailed time-resolved series of variations in the MSPs profile, polarisation, and other properties. Under this proposal, we wish to probe the profile recovery on daily timescales (3 times per week with 2 day intervals in between), revealing additional short timescale behaviours, indicative of changes in the magnetosphere which are not available to other telescopes in the world, thanks to the Parkes UWL. This will also allow us to determine if the magnetosphere has returned to its original configuration or is settling into a new one. Understanding the recovery of this event is key for demonstrating that such pulsars are still viable clocks for use in gravitational wave studies, and in turn, provide us with new data on how the normally stable magnetosphere of this millisecond pulsar responds to an impulsive change in state.

PSR J1713+0747是一颗稳定性极强的毫秒脉冲星（millisecond pulsar, MSP），因其高信噪比、窄脉冲轮廓以及长期观测积累的观测数据，被全球脉冲星计时阵列观测项目列为优先观测目标。2021年4月，该脉冲星发生了与磁层变化相关的显著事件，表现为脉冲轮廓出现可观测的改变。此后该脉冲星一直处于缓慢恢复状态，我们计划通过高频次观测，获取其脉冲轮廓、偏振特性及其他属性的高时间分辨率变化时序数据。基于本观测提案，我们将以日为时间尺度开展轮廓恢复过程的观测（每周观测3次，两次观测间隔2天），以期捕捉到全球其他望远镜无法观测到的短时标演化特征——这类特征可反映磁层的动态变化。依托帕克斯超宽波段接收机（Parkes UWL），这一观测计划还将帮助我们确认该脉冲星的磁层是否已恢复至初始结构，或是正逐步稳定至新的结构。阐明此次事件后的恢复过程，对于证明这类毫秒脉冲星仍可作为引力波研究中的可靠计时天体至关重要，同时也能为我们揭示这类通常保持稳定的毫秒脉冲星磁层在遭遇突发状态改变时的响应机制提供全新的观测数据。