Accretion disc physics: breaking the symmetries

吸积盘物理：打破对称性

基本信息

批准号：
ST/M005917/1
负责人：
Christopher Nixon
金额：
$ 59.6万
依托单位：
University of Leicester
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2015
资助国家：
英国
起止时间：
2015 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FM005917%2F1
关键词：
Accretion disc physics breaking symmetries

项目摘要

My research is concerned with astronomical systems called accretion discs. In these systems, a disc of gas orbits in the gravity field of a central star or black hole, balancing the gravitational pull of the star by the centrifugal effect of its rotation. Our Solar System formed out of a disc like this: first some of the rotating gas near the centre made the Sun itself, and then some of the gas further out formed planets, and these continue to revolve in the same orbits today.Accretion discs are the essential ingredient for a vast range of other astrophysical phenomena as well. Gas falling in the gravity of a black hole forms a disc for the same reason that planets orbit our Sun. The gas in the disc spirals slowly on to a black hole from a disc, heating up and emitting light as it does. As it falls (or "accretes") on to the black hole it emits up to 40% of its rest mass energy as light which we can observe. This makes accreting black holes the most luminous objects in the Universe. We can observe their accretion discs at distances approaching the entire extent of the Universe. Their light has taken almost the entire age of the Universe to reach us, so they show us how things were when the first stars and galaxies were forming. Understanding accretion discs is essential to understanding the Universe as a whole. But the way we currently try to picture them is too simple.Even today almost every discussion of discs assumes - essentially for convenience - that they have the simplest possible geometry, with gas orbiting the central object in a single plane, and on smooth circular orbits. This approach prevents us considering real physical effects which underly observed phenomena.My research aims to remove these symmetries by relaxing assumptions made about initial conditions and input physics. This approach has already revealed new disc processes in the last couple of years, and these offer cogent explanations of previously mysterious observed phenomena. I propose to simulate more complete systems with this first principles approach. Using state-of-the-art numerical methods, this work will have a wide impact, and constitute a big change to the standard picture of the field. It will connect to data from a vast range of new observing facilities, both space and ground based. I anticipate that it will significantly change the way we understand various pressing problems, such has how stars and planets form, and how black holes can grow to masses many millions of times greater than the Sun.

我的研究与称为增生光盘的天文系统有关。在这些系统中，中央恒星或黑洞的重力场中的气轨盘通过其旋转的离心效应来平衡恒星的重力。我们的太阳系是由这样的光盘形成的：首先，中心附近的一些旋转气体使太阳本身产生也是许多其他天体物理现象的基本要素。落入黑洞的重力的气体形成圆盘，其行星横向我们的太阳横向。圆盘中的气体从圆盘上缓慢旋转到黑洞上，加热并像发光一样发光。当它落在黑洞上（或“积聚”）时，我们可以观察到的光线最多可散发出其剩余的质量能量的40％。这使得黑洞成为宇宙中最发光的物体。我们可以在接近宇宙范围的距离处观察它们的积聚光盘。他们的光几乎占据了宇宙的整个时代才能到达我们，因此他们向我们展示了第一批恒星和星系形成时的情况。理解积聚光盘对于理解整个宇宙至关重要。但是我们目前试图描绘它们的方式太简单了。即使今天几乎每次讨论碟片都假设 - 本质上是为了方便起见 - 它们具有最简单的几何形状，气体在单个飞机上绕中心物体绕，并在光滑的圆形轨道上绕中心对象。。这种方法阻止了我们考虑基本观察到现象的实际物理效应。我的研究旨在通过放松对初始条件和输入物理的假设来消除这些对称性。在过去的几年中，这种方法已经揭示了新的光盘过程，这些方法提供了以前神秘的观察到的现象的说明。我建议通过第一个原理方法模拟更完整的系统。使用最先进的数值方法，这项工作将产生很大的影响，并构成了该领域标准情况的重大变化。它将连接到来自大量新观测设施的数据，包括空间和地面。我预计它将大大改变我们理解各种紧迫问题的方式，例如，恒星和行星的形成方式以及黑洞如何长到数百万倍的群众比太阳大。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Extreme variability in an active galactic nucleus: Gaia16aax

DOI：
10.1093/mnras/staa186
发表时间：
2020-01
期刊：
Monthly Notices of the Royal Astronomical Society
影响因子：
4.8
作者：
G. Cannizzaro;M. Fraser;P. Jonker;J. Pringle;S. Mattila;P. Hewett;T. Wevers;E. Kankare;Z. Kostrzewa
通讯作者：
G. Cannizzaro;M. Fraser;P. Jonker;J. Pringle;S. Mattila;P. Hewett;T. Wevers;E. Kankare;Z. Kostrzewa

Partial Stellar Disruption by a Supermassive Black Hole: Is the Lightcurve Really Proportional to $t^{-9/4}$?

超大质量黑洞的部分恒星扰乱：光曲线真的与 $t^{-9/4}$ 成正比吗？