Diffusive shock acceleration and magnetic field amplification

扩散冲击加速和磁场放大

• 批准号: ST/H001948/1
• 负责人: Anthony Bell
• 金额: $ 47.24万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FH001948%2F1
• 关键词: Diffusive; shock; acceleration; magnetic; field

Explosive events and supersonic flows are a feature of many of the most interesting objects in the universe. Explosions naturally produce shocks, and shocks naturally produce large numbers of very energetic particles such as those that arrive at the Earth as cosmic rays. These energetic particles are responsible for emission from long wavelength radio waves to extremely short wavelength gamma rays. This emission give us much of our information about astrophysical processes. We understand the general processes by which shocks accelerate energetic particles, but the detailed processes are less well understood. As the particle are accelerated they attempt to escape the shock, and in the process they set the surrounding medium into motion, which winds up the magnetic field lines and produces greatly increased magnetic field. The magnetic field deflects the trajectories of the accelerating particles and stops them escaping so they continue to be accelerated and eventually reach very high energies. Important breakthroughs in recent years have been x-ray observations which tell us that the magnetic field is stronger than previously thought and the development of a new theory of how accelerating particles produce the amplified field. The overall aim of the project is to investigate these processes using computer simulation. We will use a computer model to predict the strength of the magnetic field and the energy spectrum of the accelerated particles. We will then compare the computer predictions with a wide range of observations. This will help us to understand some of the most explosive and exotic phenoemna in the universe.

爆炸事件和超音速流是宇宙中许多最有趣的物体的特征。爆炸自然会产生冲击波，冲击波自然会产生大量高能粒子，比如那些以宇宙射线的形式到达地球的粒子。这些高能粒子负责从长波长无线电波到极短波长伽马射线的发射。这种辐射给了我们很多关于天体物理过程的信息。我们了解冲击波加速高能粒子的一般过程，但详细过程还不太清楚。当粒子被加速时，它们试图逃离冲击，在这个过程中，它们使周围的介质运动，这使磁力线缠绕并产生大大增加的磁场。磁场偏转加速粒子的轨迹，阻止它们逃逸，使它们继续加速，最终达到非常高的能量。近年来的重要突破是x射线观测，它告诉我们磁场比以前认为的要强，以及加速粒子如何产生放大场的新理论的发展。该项目的总体目标是使用计算机模拟来研究这些过程。我们将使用计算机模型来预测磁场的强度和加速粒子的能谱。然后，我们将计算机预测与广泛的观察进行比较。这将有助于我们了解宇宙中一些最具爆炸性和异国情调的phenoemna。

项目成果

Turbulent amplification of magnetic fields in laboratory laser-produced shock waves

• DOI: 10.1038/nphys2978
• 发表时间: 2014-07-01
• 期刊: NATURE PHYSICS
• 影响因子: 19.6
• 作者: Meinecke, J.;Doyle, H. W.;Gregori, G.
• 通讯作者: Gregori, G.

Cosmic ray acceleration

• DOI: 10.1016/j.astropartphys.2012.05.022
• 发表时间: 2013-03-01
• 期刊: ASTROPARTICLE PHYSICS
• 影响因子: 3.5
• 作者: Bell, A. R.

Cosmic-ray acceleration and escape from supernova remnants

• DOI: 10.1093/mnras/stt179
• 发表时间: 2013-05-01
• 期刊: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
• 影响因子: 4.8
• 作者: Bell, A. R.;Schure, K. M.;Giacinti, G.
• 通讯作者: Giacinti, G.

Universal behaviour of shock precursors in the presence of efficient cosmic ray acceleration

存在有效宇宙射线加速时激波前兆的普遍行为

• DOI: 10.1093/mnras/stt100
• 发表时间: 2013
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Reville B

Modelling the interaction of thermonuclear supernova remnants with circumstellar structures: the case of Tycho's supernova remnant

• DOI: 10.1093/mnras/stt1406
• 发表时间: 2013-07
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: A. Chiotellis;D. Kosenko;K. Schure;J. Vink;J. Kaastra