Parkes observations for project P1172 semester 2022OCTS_05

PSR J1713+0747 is an extremely stable millisecond pulsar used in global pulsar timing array campaigns as a high priority pulsar because of its strong S/N, narrow profile and long-term observation history. In April 2021, the pulsar experienced a significant event related to a change in its magnetosphere, presented as an observable change in the pulsar’s profile. Since then, the pulsar has been slowly recovering and we wish to observe it with high cadence 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 daily timescales (3 times per week with 2 day intervals in between), 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是一颗稳定性极强的毫秒脉冲星（millisecond pulsar），因其信噪比高、轮廓狭窄且拥有长期观测历史，被纳入全球脉冲星计时阵列（pulsar timing array, PTA）巡天项目的高优先级观测清单。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，表现为其脉冲轮廓出现可观测的改变。自此之后，该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，获取该毫秒脉冲星轮廓、偏振（polarisation）及其他物理特性的高时间分辨率变化序列。基于本观测提案，我们将以日级时间尺度开展轮廓恢复过程的监测（每周3次，两次观测间隔2天），以此捕捉全球其他望远镜无法观测到的额外短时标行为——这类行为可直观反映磁层的内部变化，这一优势得益于帕克斯超宽波段系统（Parkes UWL）的观测能力。本次观测还将帮助我们判断该磁层是否已恢复至初始构型，或是逐渐稳定至全新的状态。阐明此次事件的恢复过程，对于验证这类毫秒脉冲星仍可作为引力波研究中的可靠时钟至关重要；同时也能为我们揭示这颗通常处于稳定状态的毫秒脉冲星，其磁层在受到突发状态改变后的响应机制提供全新的观测数据。