Parkes observations for project P1162 semester 2023APRS_11

Pulsar timing is a powerful tool in studying pulsar physics. Discovering more exotic pulsar systems or timing pulsars with higher precision is an essential part of pulsar astronomy. As a recently discovered millisecond pulsar, PSR J1402+13 is an interesting source for follow-up timing observations. First, its apparent spin-down rate is the highest among known millisecond pulsars. This spin-down rate, if confirmed, will place stringent constraints on the spin-up process predicted by pulsar recycling theories. Second, and more importantly, preliminary analysis shows that J1402+13 is a very promising candidate for pulsar timing arrays, with an achievable precision at the level of 6 nanoseconds for 60 minutes observation with Parkes. We have observed J1402+13 for 8 times in the past two months and propose to continue the observations in the coming semester. We apply for another 14 hours to observe the pulsar to extend the timing baseline to one year. This project will derive an ephemeris of the system, which is valuable to understand its formation and evolution history. Furthermore, the observations will allow us to evaluate the timing performance of J1402+13 and its suitability to be included in pulsar timing arrays.脉冲星计时是研究脉冲星物理学的强有力工具。发现更多奇异脉冲星系统，或以更高精度开展脉冲星计时观测，是脉冲星天文学研究的核心环节之一。作为新近发现的毫秒脉冲星（millisecond pulsar），PSR J1402+13是后续计时观测的极具研究价值的目标源。其一，其视自转减慢速率（spin-down rate）在已知毫秒脉冲星中位列最高；若该自转减慢速率得到证实，将对脉冲星回收理论（pulsar recycling theories）所预言的自转加速过程施加严苛的约束条件。其二，也是更为关键的一点：初步分析表明，J1402+13是脉冲星计时阵列（pulsar timing arrays）极具潜力的候选源，使用帕克斯（Parkes）望远镜开展60分钟观测即可达到6纳秒级的计时精度。过去两个月内，我们已对J1402+13开展了8次观测，并计划在接下来的观测周期内继续相关观测工作。我们申请额外14小时的观测时长，以将该源的计时基线延长至一年。本项目将获取该脉冲星系统的星历表（ephemeris），这对揭示其形成与演化历史具有重要价值。此外，本次观测还将帮助我们评估J1402+13的计时性能，以及其能否被纳入脉冲星计时阵列的适配性。