Radio polarisation properties of neutron stars

射电望远镜可以探测到的周期性脉冲是射电望远镜的主要特征。产生这些无线电脉冲的恒星是中子星，质量约为1.5个太阳质量，半径仅为10公里的超密度恒星。射电望远镜将粒子加速到相对论速度，然后粒子沿着其极强磁场的磁力线运动。当这些粒子产生的无线电辐射束扫过地球（就像一个“灯塔”）时，我们希望它描述一个特定的偏振变化，这可以告诉我们脉冲星的几何细节，包括它的旋转和磁轴的位置，然而事实证明它比这更复杂，并且让我们瞥见了发射过程本身的电动力学。在这个项目中，你将研究双光子晶体的偏振特性。您将从Jodrell Bank天文台的Lovell射电望远镜的数据开始，充分利用其新的偏振能力。这将得到澳大利亚帕克斯望远镜和LOFAR的数据的补充，LOFAR是一个在非常低的频率下运行的大型下一代射电望远镜阵列。该项目涉及数据分析和建立一个计算机模型，描述脉冲星磁层的物理学，其中将包括各种相对论效应。该模型将被用来提供一个自我一致的图片，可以描述你的数据，这是目前过于简化的“标准”模型失败。

The defining characteristic of radio pulsars is their periodic pulses which can be detected by radio telescopes. The stars that generate these radio pulses are neutron stars, super dense stars with a mass of ~1.5 solar masses and a radius of only ~10 km. Radio pulsars accelerate particles to relativistic speeds which then move along the field lines of their extremely strong magnetic fields. As the beam of radio emission that these particles generates sweeps across the Earth (like a "light house") we expect it to describe a specific change in polarisation which can tell us details of the geometry of the pulsar, including the location of its rotation and magnetic axes, however it turns out to be more complicated than this and is giving us a glimpse of the electrodynamics of the emission process itself. In this project you will investigate the polarization properties of pulsars. You will start with data from the Lovell radio telescope at Jodrell Bank Observatory, making full use of its new polarization capability. This will be supplemented with data from the Parkes telescope in Australia and LOFAR, a large next generation array of radio telescopes operating at very low frequencies. This project involves data analysis and building a computer model describing the physics of the pulsar magnetosphere, which will include various relativistic effects. The model will be used to provide a self-consistent picture which can describe your data, for which the currently oversimplified "standard" model fails.