Parkes observations for project P1172 semester 2023APRS_10

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, PTA）观测项目中极具关键价值的毫秒脉冲星（millisecond pulsar, MSP），其凭借悠久的长期观测历史、极为稳定且轮廓狭窄的脉冲轮廓，以及极高的信噪比（Signal-to-Noise Ratio, S/N），成为该领域的核心观测目标。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改变。自事件发生以来，这颗毫秒脉冲星始终处于缓慢恢复的过程中，我们计划通过高频次观测追踪这一恢复进程，以构建该脉冲星轮廓、偏振特性及其他属性随时间变化的精细时间分辨序列。基于本观测提案，我们拟以周为时间尺度开展轮廓恢复过程的监测（每月内每周观测一次），以期揭示此前未被捕捉到的短时标行为。这类行为可反映磁层的变化，而依托帕克斯超宽波段接收机（Parkes UWL），我们能够获取全球其他望远镜无法获得的此类观测数据。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，或是正逐渐稳定于新的磁层状态。阐明此次事件后的恢复过程，对于证实此类毫秒脉冲星仍可作为引力波研究中的可靠计时基准至关重要；同时也能为我们揭示这类通常处于稳定状态的磁层，如何响应突发性的状态改变提供全新的观测数据。