Parkes observations for project P1162 semester 2022OCTS_07

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 spin-down rate is the highest among known millisecond pulsars according to initial data. This spin-down rate, if confirmed, will place stringent constraints on the spin-up process predicted by pulsar recycling theories. Second, and more importantly, 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 thus apply for 18.7 hours to conduct dedicated timing observations of J1402+13 over the period of half a year (and more observations in the future semesters). 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（Pulsar timing）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，或是以更高精度开展脉冲星计时观测，均是脉冲星天文学研究的核心内容。作为新近发现的毫秒脉冲星（millisecond pulsar），PSR J1402+13是后续计时观测中极具研究价值的目标源。其一，根据初始观测数据，该星的自转减慢率（spin-down rate）在已知毫秒脉冲星中居于首位；若该自转减慢率得到证实，将对脉冲星回收理论所预言的自转加速过程施加极强的约束。其二，也是更为关键的一点：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分钟观测时，可实现6纳秒级的计时精度。有鉴于此，我们申请了18.7小时的观测时长，用于在半年周期内开展针对J1402+13的专属计时观测（后续学期还将申请更多观测时长）。本项目将构建该系统的星历表（ephemeris），这对厘清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，以及其能否适配并加入脉冲星计时阵列。