Parkes observations for project P1172 semester 2023APRS_06

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）项目具有关键意义的毫秒脉冲星（millisecond pulsar, MSP），其拥有长期观测历史、轮廓高度稳定且窄化，且信噪比（signal-to-noise ratio, S/N）优异。2021年4月，该脉冲星发生了一起与其磁层（magnetosphere）变化相关的显著事件，表现为脉冲轮廓出现可观测的异常变化。自该事件发生以来，这颗脉冲星一直在缓慢恢复。我们希望通过高时间分辨率观测追踪这一恢复过程，以获取该毫秒脉冲星轮廓、偏振及其他属性的高分辨时间演化序列。依托本观测提案，我们计划以周为时间尺度（每月保持每周一次的观测频次）来探测其轮廓恢复过程，借助Parkes UWL的观测优势，捕捉其他望远镜无法观测到的短时标行为——这类行为可用于指示磁层的内部变化。本次观测还将帮助我们判定，该脉冲星的磁层是否已恢复至初始构型，或是正逐渐稳定于全新的磁层状态。阐明此次事件后的恢复过程，对于验证此类脉冲星仍可作为引力波研究中的可靠计时时钟至关重要；同时也将为我们提供全新的观测数据，以研究这颗通常处于稳定状态的毫秒脉冲星的磁层如何响应瞬时状态扰动。