Parkes observations for project P1172 semester 2022OCTS_07

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是一颗极端稳定的毫秒脉冲星（millisecond pulsar, MSP），因其信噪比（signal-to-noise ratio, S/N）优异、脉冲轮廓狭窄且拥有长期观测积累数据，被全球脉冲星计时阵列观测项目列为高优先级观测目标。2021年4月，该脉冲星发生了一次与磁层变化相关的显著事件，表现为其脉冲轮廓出现可观测的形态改变。此后，该脉冲星一直在缓慢恢复过程中，我们计划以高观测频次开展针对性观测，以获取该毫秒脉冲星轮廓、偏振特性及其他属性的高时间分辨率详细变化序列。基于本观测提案，我们将以每日时间尺度开展轮廓恢复过程的监测（每周开展3次观测，两次观测间隔2天），以此揭示此前未被捕捉到的短时标行为——此类行为可反映磁层的动态变化，而借助帕克斯超宽波段接收机（Parkes UWL），此类观测是全球其他望远镜无法实现的。本研究还将帮助我们判断该磁层是否已恢复至初始构型，或是正逐渐稳定于新的平衡状态。阐明此次事件的恢复过程，对于证明此类脉冲星仍可作为引力波研究中的可靠时钟至关重要；同时也能为我们提供全新的观测数据，以解析这类通常保持稳定的毫秒脉冲星磁层是如何响应突发性状态改变的。