Parkes observations for project P1172 semester 2023APRS_11

PSR J1713+0747 is a very important millisecond pulsar for global pulsar timing array campaigns, due to its long-term observation history, very stable and narrow profile and strong S/N. In April 2021, the pulsar experienced a significant event related to a change in its magnetosphere, presented as an observable change in the pulsar profile. Since then, the pulsar has been slowly recovering and we wish to observe this recovery with high-cadence observations 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 weekly timescales (once per week per month), 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是一颗对全球脉冲星计时阵列（pulsar timing array, PTA）项目具有重要意义的毫秒脉冲星（millisecond pulsar, MSP），其具备长期观测历史、极稳定的窄化脉冲轮廓与高信噪比(S/N)。
2021年4月，该脉冲星发生了一次与其磁层变化相关的显著事件，表现为脉冲轮廓的可观测改变。自事件发生以来，该脉冲星始终处于缓慢恢复状态，我们期望通过高频次观测追踪这一恢复过程，以获取该毫秒脉冲星的脉冲轮廓、偏振特性及其他属性的高时间分辨变化序列。
基于本观测提案，我们计划以周级时间尺度（每月每周开展一次观测）对脉冲轮廓的恢复过程进行探测，借此揭示其他全球望远镜无法观测到的短时标行为——这类行为可反映磁层的内部变化，而这一优势得益于帕克斯UWL设备的支持。此外，本次观测还将帮助我们判断该脉冲星的磁层是否已恢复至初始构型，或是正逐渐稳定至新的运行状态。
阐明此次事件后的恢复过程，是证明这类毫秒脉冲星仍可作为引力波研究中可靠计时工具的关键；同时也能为我们提供全新的观测数据，用以揭示这颗通常处于稳定状态的毫秒脉冲星的磁层如何响应突发性状态变化。