The manifestations of thermal instabilities in accretion discs

吸积盘热不稳定性的表现

• 批准号: 2265944
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2265944
• 关键词: manifestations; thermal; instabilities; accretion; discs

Accretion discs are found in a large number of astrophysical situations. They form when matter falls under gravity towards a central, often compact, body. Due to angular momentum in the material, it settles into a disc around the central body. Viscous forces in the disc cause material to move inwards and accrete onto the central object.A simplified analytical theory of these discs suggests that they should be unstable to thermal fluctuations (ie they should catastrophically heat or cool). There is no indication in observations that this happens in nature, and the reason for this is still poorly understood.We aim to explore this problem, starting with extensions to the simplified analytical theory involving stochastic processes. Our eventual plan is to construct large scale computer simulations which will enable us to study these phenomena (or lack thereof) in detail.

吸积盘在大量的天体物理学情况下被发现。当物质在重力作用下向一个中心，通常是紧凑的物体下落时，它们就形成了。由于材料中的角动量，它在中心体周围形成一个圆盘。圆盘中的粘性力导致物质向内移动并吸积到中心物体上。这些圆盘的简化分析理论表明，它们应该对热波动不稳定（即它们应该灾难性地加热或冷却）。没有任何迹象表明，这种情况发生在自然界中，其原因仍然知之甚少。我们的目标是探索这个问题，从扩展到简化的分析理论，涉及随机过程。我们的最终计划是构建大规模的计算机模拟，这将使我们能够详细研究这些现象（或缺乏）。