Parkes observations for project P972 semester 2018OCTS_05

50 years after the discovery of pulsars, these objects continue to push the boundaries in the testing of fundamental physics, most notably in General Relativity and in understanding the equation of state of cold, dense, nuclear matter. A number of pressing open questions remain, as basic as understanding pulsar orientation and radio beam geometry, and as complicated as understanding the plasma conditions that set their spectrum and degree of polarisation. Progress has mainly been limited by telescope sensitivity and simultaneous frequency coverage. The Parkes Ultra-Wideband receiver will change the game. We propose observations focused on a small group of bright pulsars to answer key questions on the pulsar emission process. We focus on three key observables, measured in individual pulses and average pulse profiles, across the widest available frequency range: the total power, the linear and circular polarisation, and the polarisation position angle profile across the pulse. The data will allow us to separate intrinsic emission properties from propagation effects in the pulsar magnetosphere and the interstellar medium, in a way that has never before been possible.自脉冲星被发现以来的半个世纪里，这类天体仍在不断推动基础物理检验的边界，尤其在广义相对论（General Relativity）研究，以及理解冷密核物质物态方程的领域中持续发挥关键作用。目前仍存在诸多亟待解决的开放性问题：小到阐明脉冲星取向与射电波束几何结构这类基础课题，大到解析决定其光谱与偏振（polarisation）度的等离子体环境这类复杂议题。此前相关研究的进展主要受限于望远镜的灵敏度与同时性频率覆盖范围。帕克斯（Parkes）超宽带接收机将彻底扭转这一局面。我们提议针对一小批明亮脉冲星开展观测，以解答脉冲星辐射机制相关的核心问题。本次研究将聚焦三类核心可观测物理量：在最宽可用频率范围内，对单脉冲与平均脉冲轮廓进行测量，具体包括总功率、线偏振（linear polarisation）与圆偏振（circular polarisation），以及脉冲全程的偏振位置角（polarisation position angle）轮廓。这批观测数据将使我们能够以史无前例的方式，将脉冲星磁层（pulsar magnetosphere）与星际介质（interstellar medium）中的传播效应与辐射本征特性分离开来。