Parkes observations for project P1172 semester 2023APRS_01

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是一颗在全球脉冲星计时阵列（pulsar timing array）观测计划中至关重要的毫秒脉冲星（millisecond pulsar），其具备长期观测历史、轮廓极为稳定且狭窄，同时信噪比（S/N）优异。2021年4月，该脉冲星发生了一场与其磁层（magnetosphere）变化相关的显著事件，表现为脉冲星轮廓出现可观测的改变。自该事件发生以来，这颗毫秒脉冲星一直在缓慢恢复，我们希望通过高频次观测追踪此次恢复过程，以获取详细的时间分辨序列，刻画该毫秒脉冲星的轮廓、偏振（polarisation）及其他属性的变化。依托帕克斯超宽频带（Parkes UWL）设备，我们计划在周时间尺度上（每月内每周开展一次观测）对其轮廓恢复过程进行探测，以揭示额外的短时标演化特征——这类特征可指示磁层发生了全球其他望远镜无法捕捉到的变化，这一观测计划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，或是正逐渐稳定为全新构型。厘清此次事件后的恢复过程，是证明此类毫秒脉冲星仍可作为引力波研究中可靠计时源的关键，同时也将为我们提供全新的数据，以揭示这颗通常状态稳定的毫秒脉冲星的磁层是如何响应一次突发性状态改变的。