Establishing the Fundamental Physics and Interactions of Coherent Radio and Thermal X-ray Emission from Pulsars

脉冲星是快速旋转的、高度磁化的、非常致密的恒星，它们是在50多年前被发现的。脉冲星发出的光通常以无线电波或X射线的形式被探测到。无线电波是由沿着脉冲星磁场线流动的带电等离子体发射的，而X射线是由回流等离子体加热的非常热的（因此是“热”）表面发射的。虽然脉冲星无线电和x射线发射的大致情况是已知的，但许多细节尚未完全了解。佛蒙特大学的一个研究小组将执行一个由三部分组成的观测和理论计划，旨在深入了解脉冲星发射机制，并研究银河系的星际磁场。无线电观测已经或将主要通过甚大阵列、阿雷西博、LOFAR和格林班克进行。利用xmm -牛顿卫星进行了x射线观测。该计划的第一部分包括确认和扩展脉冲星射电发射物理。第二部分将把热x射线与无线电发射连接起来。第三部分将使用脉冲星测量来帮助理解我们银河系平面上的磁场。本科生将广泛参与这些项目，并将获得宝贵的科学训练，而这些训练在课堂上是无法获得的。通过对脉冲星磁层的观测解释和计算机建模，天文学家现在了解了电荷流是如何产生的以及它们在哪里流动，概述了脉冲星射电发射的广泛机制：它是在哪里产生的，部分是如何逃逸的。计划中的研究将提高发射物理学与全球磁层过程联系起来的能力，并为理论家开发带电孤子辐射的物理模型提供所需的特异性。研究小组还将同时对具有多种发射状态的脉冲星进行x射线和射电观测，以了解与热x射线发射相关的回流加热如何与射电发射特性的变化联系在一起，并将确定候选脉冲星，用于未来的x射线/射电联合研究。我们对银河系磁场的性质、结构和起源只了解了一部分。该项目将包括分析广泛的，现有的脉冲星法拉第旋转测量遥远和微弱的脉冲星，为理解我们银河系平面上的磁场做出重大贡献。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Pulsars are rapidly spinning, highly magnetized, and very compact stars, which were discovered just over fifty years ago. The light from pulsars is usually detected as radio waves or X rays. The radio waves are emitted from charged plasma flowing along the pulsar's magnetic field lines, while the X rays are emitted from very hot (hence "thermal") surface areas, heated by backflowing plasma. While the broad picture of pulsar radio and X-ray emission is known, many of the details are yet to be fully understood. A research team at the University of Vermont will carry out a three part observational and theoretical program aimed at providing insight into pulsar emission mechanisms and studying the Milky Way's interstellar magnetic field. The radio observations have been or will be conducted primarily with the Very Large Array, Arecibo, LOFAR and Green Bank. X-ray observations have been made using the XMM-Newton satellite. The first part of the program involves confirmation and extension of pulsar radio emission physics. The second part will connect thermal X-ray to radio emission. The third part will use pulsar measurements to help to understand the magnetic field in the plane of our Galaxy. Undergraduate research students will be extensively involved in the projects and will receive invaluable scientific training that is simply not available in the classroom.Through observational interpretation and computer modeling of the pulsar magnetosphere, astronomers now understand how charge currents are generated and where they flow, outlining the broad mechanisms of pulsar radio emission: where it is generated and how part of it escapes. The planned study will advance capabilities to relate the emission physics to global magnetospheric processes, and provide the needed specificity for theorists to develop physical models for charged soliton radiation. The research team will also use simultaneous X-ray and radio observations of pulsars with multiple emission states in order to learn how the backflow heating associated with thermal X-ray emission is connected to changes in the radio emission properties, and will identify candidate pulsars for future joint X-ray/radio investigations. The nature, structure, and origin of the Galactic magnetic field is only partially understood. The project will include analyses of extensive, existing pulsar Faraday rotation measurements of distant and faint pulsars to contribute significantly to the understanding of the magnetic field in the plane of our Galaxy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.