Parkes observations for project P1362 semester 2025OCTS_02

PSR J1757-1854 is the most relativistic galactic double neutron star system. Its eccentricity makes it an ideal playground for gravity experiments with pulsar timing. Via observations of its profile evolution, we can constraint its rate of geodetic precession. Currently, there are four possible geometric configurations that explain the time evolution of the polarisation swing. The geodetic precession and the Lense-Thirring effect will eventually manifest themselves in the post-Keplerian parameters within the next decade, allowing for two further tests of gravity. We propose a single observation with a maximum integration of ~8 hours allowed by LST time for this semester. We will inspect the polarisation properties of this observation, and we will add the ToAs to a global timing campaign. These observations will be added to joint GBT and (past) MeerKAT observations, and they will be part of a long-term, global observational program of this pulsar.

PSR J1757-1854是银河系内相对论性最强的双中子星系统。其轨道偏心率使其成为开展脉冲星计时引力实验的绝佳平台。通过观测其脉冲轮廓的演化过程，我们可以约束测地进动的速率。目前已有四种可行的几何构型可解释该系统偏振摆动的时间演化规律。测地进动与兰斯-蒂林效应（Lense-Thirring effect）将在未来十年内体现在开普勒后参数（post-Keplerian parameters）中，从而可开展两项额外的引力检验实验。本项目组计划于本学期开展单次观测，单次观测的最长积分时长可达地方恒星时（LST）允许的约8小时。我们将分析本次观测的偏振特性，并将测得的脉冲到达时间（Time of Arrival, ToAs）纳入全球脉冲星计时合作项目。本次观测数据将与绿岸望远镜（GBT）及过往米尔特卡望远镜（MeerKAT）的联合观测数据整合，并纳入该脉冲星的长期全球观测计划。