Parkes observations for project P1172 semester 2023APRS_12

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）项目至关重要的毫秒脉冲星（millisecond pulsar, MSP），其拥有长期观测历史、脉冲轮廓极为稳定且狭窄，同时具备极高的信噪比（signal-to-noise ratio, S/N）。2021年4月，该脉冲星发生了一次与磁层（magnetosphere）变化相关的显著事件，表现为脉冲轮廓出现可观测的改变。自该事件发生以来，这颗脉冲星一直在缓慢恢复。我们希望通过高密度时序观测对其恢复过程进行追踪，以获取该毫秒脉冲星的脉冲轮廓、偏振（polarisation）及其他属性随时间变化的详细时间分辨序列。基于本观测提案，我们计划以周为时间尺度开展探测，具体为每月内每周观测一次，以期揭示更多短时标行为特征——这类特征能够反映磁层的变化，而依托帕克斯UWL，我们可获取全球其他望远镜无法获得的此类观测数据。这将帮助我们判断该磁层是否已恢复至初始构型，或是正逐渐稳定于全新的状态。深入理解此次事件的恢复过程，是证明此类脉冲星仍可作为引力波（gravitational wave）研究中可靠计时钟的关键；同时也能为我们提供全新的数据，用以解析这颗通常状态稳定的毫秒脉冲星的磁层如何对突发性状态改变做出响应。