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Activity of Strongly Magnetized Neutron Stars

强磁化中子星的活动

基本信息

批准号：
2009453
负责人：
Andrei Beloborodov
金额：
$ 63.64万
依托单位：
Columbia University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009453&HistoricalAwards=false
关键词：
Activity Strongly Magnetized Neutron Stars

项目摘要

Extremely dense stellar remnants, known as neutron stars (NS), are not quiet objects. They are known to have quakes in their crusts, which can produce bright bursts of radiation. Like earthquakes allow geologists to study the interior of the Earth, neutron star quakes allow astronomers to probe the star’s interior, one of the most important questions in high-energy astrophysics. A research group at Columbia University will use computer simulations to model NS quakes and their interactions with the NS magnetosphere, to better understand observational phenomena such as NS timing glitches, bursts from highly magnetized NS called magnetars, giant NS flares, electromagnetic precursors of neutron star mergers, and perhaps even solve the production of mysterious fast radio bursts (FRBs), which may arise from magnetars. More generally, theoretical astrophysics has a broader impact through promoting knowledge about our universe and through education. The results of the proposed research will be disseminated at conferences and taught as part of high-energy astrophysics course at Columbia University. The research will involve training of graduate and undergraduate students. First-principle simulations of magnetospheric emission from a quake are novel and will significantly advance the field. The research group has developed a new code that follows the spreading of shear waves excited by a quake into the entire crust, the liquid core, and the magnetosphere. The magnetospheric activity will be examined using an advanced plasma code developed by the group and designed for global kinetic simulations of electron-positron discharge around neutron stars. The proposal has two parts. (1) First-principle simulations of the magnetospheric response to crustal quakes and calculation of the produced radiation. The simulation method will be used to investigate two phenomena: (a) The recently discovered choking of the Vela pulsar during a spin glitch. This observation likely witnessed a powerful starquake. (b) The emission of X-ray bursts by magnetar quakes, a long-standing puzzle. (2) Development of an evolutionary model of young, hyper-active magnetars. These hypothetical objects are plausible engines of cosmological FRBs. The project focuses on the driver of hyper-activity --- ambipolar diffusion in the neutron star core --- and its effect on the magnetosphere, leading to magnetic flares and launching blast waves in the magnetar wind.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.

被称为中子星（NS）的密度极高的恒星残骸并不是安静的物体。众所周知，它们的地壳会发生地震，这会产生明亮的辐射爆发。就像地震可以让地质学家研究地球内部一样，中子星星地震可以让天文学家探测星星的内部，这是高能天体物理学中最重要的问题之一。哥伦比亚大学的一个研究小组将使用计算机模拟来模拟NS地震及其与NS磁层的相互作用，以更好地理解观测现象，如NS定时故障，来自高度磁化的NS（称为磁星）的爆发，巨大的NS耀斑，中子星星合并的电磁前兆，甚至可能解决神秘的快速无线电爆发（FRB）的产生，这可能来自磁星。更广泛地说，理论天体物理学通过促进对我们宇宙的了解和教育产生了更广泛的影响。拟议研究的结果将在会议上传播，并作为哥伦比亚大学高能天体物理学课程的一部分进行教学。这项研究将涉及对研究生和本科生的培训。第一原理模拟地震产生的磁层辐射是新颖的，将大大推进该领域。该研究小组已经开发出一种新的代码，它可以跟踪地震激发的剪切波传播到整个地壳，液核和磁层。磁层活动将使用该小组开发的先进等离子体代码进行检查，该代码是为中子星周围电子-正电子放电的全球动力学模拟而设计的。该提案有两个部分。(1)磁层对地壳地震响应的第一性原理模拟及产生辐射的计算。模拟方法将用于研究两种现象：（a）最近发现的船帆座脉冲星在自旋故障期间的阻塞。这次观测很可能见证了一次强大的星震。(b)磁星地震发射X射线爆发是一个长期存在的难题。(2)年轻超活跃磁星演化模型的发展。这些假想的物体是宇宙学FRB的合理引擎。该项目的重点是超活跃的驱动因素-中子星星核心的双极扩散-及其对磁层的影响，导致磁耀斑和在磁星风中发射爆炸波。该奖项反映了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。