Origin and evolution of cosmic magnetism

宇宙磁力的起源和演化

• 批准号: RGPIN-2019-04848
• 负责人: Stil, Jeroen
• 金额: $ 1.75万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=679911
• 关键词: Origin; evolution; cosmic; magnetism

Observations show that magnetic fields are ubiquitous in the cosmos. Together with gravity, cosmic magnetic fields direct the flow of plasma and cosmic rays, and, indirectly, the motion of neutral gas. Still, we cannot answer basic questions about the structure of cosmic magnetic fields, the origin of large-scale magnetic fields in galaxies, and the properties of turbulence in magnetized plasma in space. Our lack of understanding of cosmic magnetic fields leaves major gaps in the physics of galaxy evolution, from the retention of hot gas and cosmic rays in the disk to support of cold molecular clouds against gravitational collapse.******Galaxies represent the visible part of structure in the universe. It is here that stellar nucleosynthesis builds elements beyond hydrogen, helium and lithium. After nearly 14 billion years of evolution, all observable gas appears enriched by the products of stellar nucleosynthesis, even in intergalactic space. This fact bears testimony to the impact that the life cycle of stars on a galactic scale has on the evolution of galaxies and their wide environment. Some galaxies also host active galactic nuclei (AGN), that are powered by accretion of matter on a central, supermassive black hole. Beams of matter called jets are ejected at bulk relativistic speed, and form giant magnetic radio lobes in intergalactic space much larger than a galaxy. The ejection of matter, and its its associated kinetic energy and momentum, by stars and AGN is referred to as stellar feedback and AGN feedback. We cannot understand galaxy evolution without the physics of feedback.******Magnetic fields play an important role in the physics of feedback, for example during various stages of star formation, acceleration and diffusion of cosmic rays, constraining galactic outflows, and collimating jets. In turn, stellar feedback provides energy for dynamo effects that amplify magnetic fields, while outflows and jets from AGN can inject magnetic fields into the intergalactic medium. Observations that reveal the structure an dynamical importance of magnetic fields provide crucial guidance for models of feedback and turbulence.*** ***This research program targets the complex feedback processes between gas and magnetic fields in galaxies, and their relation to the emergence of cosmic magnetic fields. In the next five years, we will lead by combining measurements of the velocity of plasma and neutral gas in the local interstellar medium with measurements of the magnetic field from the energy injection scale to the smallest observable turbulence. We will address the question of how magnetic fields evolved over cosmic time in spiral galaxies and in the lobes of radio galaxies the main sites for stellar and AGN feedback. My group excels in stacking, integrated polarization of galaxies, and statistics of rotation measures. We will lead application of these techniques toward our objectives through defined science projects proposed according to survey policies. ********

观察结果表明，磁场在宇宙中无处不在。与重力一起，宇宙磁场引导血浆和宇宙射线的流动，并间接地引导中性气体的运动。尽管如此，我们仍无法回答有关宇宙磁场的结构，星系中大规模磁场的起源以及空间中磁化等离子体中湍流的特性。我们对宇宙磁场缺乏了解，从保留热气和宇宙射线到磁盘中的物理学物理学的主要差距，到支持冷分子云防止重力崩溃。********表示可见的。宇宙结构的一部分。正是在这里，恒星的核合成构建了氢，氦和锂之外的元素。经过将近140亿年的进化，即使在白术空间中，所有可观察到的气体似乎都被恒星核合成的产物富含。这一事实证明了恒星对银河系及其广泛环境的演变的影响。一些星系还容纳了主动银河核（AGN），这些核由中央，超大的黑洞上的物质增添动力。称为喷气机的物质光束以批量的相对速度弹出，并在近似星系中形成巨大的磁性无线电裂片，比银河系大得多。恒星和AGN的物质及其相关的动能和动量的射出被称为恒星反馈和AGN反馈。没有反馈的物理学，我们无法理解星系的演变。******磁场在反馈物理学中起着重要作用，例如，在恒星形成的各个阶段，加速度和宇宙射线的扩散，约束银河流量，以及限制性的银河流量和扩散准飞机。反过来，恒星反馈为放大磁场的发电机效应提供了能量，而来自AGN的流出和喷射可以将磁场注入磁场间介质。揭示结构磁场的动态重要性的观察结果为反馈和湍流模型提供了至关重要的指导。宇宙磁场。在接下来的五年中，我们将通过结合局部星际介质中血浆和中性气体速度的测量以及从能量注入量表到最小可观察的湍流的测量。我们将解决磁场在螺旋星系中以及射电星系中如何在宇宙时间演变的问题，即恒星和AGN反馈的主要位置。我的小组在堆叠，星系的综合极化以及旋转措施的统计数据方面表现出色。我们将通过根据调查政策提出的定义的科学项目来领导这些技术将这些技术应用于我们的目标。 ********