Long-term project observations for project P455 semester 2025APRS_05

This project is to continue timing and profile studies of the first double-pulsar system, a unique laboratory for gravitational physics. Important results published in our 53-page Phys. Rev. X paper (2021) include the first measurements of higher-order light-propagation effects and of the relativistic deformation of the orbit and highlight the importance of a long term observational campaign, including VLBI observations, for this remarkable system. The main aims of this proposal are to provide the strongest tests to date for general relativity and to measure for the first time the moment-of-inertia of a neutron star. Additionally, we will determine the system geometry, map the pulsar beams via geodetic precession, and search for the reappearance of Pulsar B. We exploit the high sensitivity and broad bandwidth of the UWL receiver. We are collaborating with the MeerKAT Double Pulsar Timing team to optimise combination of MeerKAT and UWL data.本项目旨在对首个双脉冲星系统（double-pulsar system）开展持续的计时与轮廓研究，该系统是引力物理学研究的独特天然实验室。我们于2021年发表在《物理评论X》（Phys. Rev. X）的53页研究论文中，取得了多项重要成果：首次测量了高阶光传播效应与轨道相对论形变，同时凸显了针对该特殊系统开展长期观测计划（包括甚长基线干涉测量（Very Long Baseline Interferometry, VLBI）观测）的重要性。本项目的核心目标是为广义相对论（general relativity）提供截至目前最为严苛的检验，并首次测量中子星（neutron star）的转动惯量。此外，我们还将测定该系统的几何结构，通过测地岁差（geodetic precession）绘制脉冲星射束分布图，并搜寻脉冲星B的重现信号。本项目将利用UWL接收机的高灵敏度与宽带宽特性。我们将与MeerKAT双脉冲星计时团队展开合作，以优化MeerKAT与UWL数据的联合处理流程。