Non-linear dynamics of hydrodynamic tori as a model of oscillations and bending waves in astrophysical discs
Non-linear dynamics of hydrodynamic tori as a model of oscillations and bending waves in astrophysical discs
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流体动力学环面的非线性动力学作为天体物理圆盘中振荡和弯曲波的模型
DOI：
10.1093/mnras/stab1554
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发表时间：
2021
影响因子：
4.8
通讯作者：
Fairbairn C
中科院分区：
文献类型：
--
作者：
Fairbairn C
了解天体物理流体中的振荡和波动有助于阐明它们的观测变异性和潜在的物理机制。事实上，吸积盘或环的整体振荡和弯曲模式可能与致密天体周围的准周期和翘曲结构有关。虽然大多数研究依赖于线性理论，但在观测上具有重要意义的非线性动力学仍然知之甚少，特别是在开普勒式圆盘中，对于这些圆盘的共振通常需要单独处理。在这项工作中，我们引入了一种新的解析模型，它精确地求解了局部剪切薄板中非自重椭圆柱体的理想可压缩流体方程。环的纵横比是一个可调节的参数，允许从圆形截面的环面到薄环的模型的连续统。我们将注意力限制在作为坐标的线性函数的流场上，捕捉最低阶的全局运动，并将动力学简化为一组耦合的常微分方程组(ODE)。该系统作为一个框架，用于探索大振幅和开普勒式区域中的一系列丰富的流体动力学现象。在这个模型中，我们证明了倾斜圆环和翘曲圆盘之间的联系，表明环的线性模式对应于相对精确的全局弯曲模式。这些在基于数值网格的模拟中得到了进一步证实。至关重要的是，这里开发的ODE系统允许对非线性动力学进行更容易的调查。这一点将在随后的一篇论文中得到证明，该论文证明了薄倾斜环中翘曲和垂直运动之间的模式耦合。
Understanding oscillations and waves in astrophysical fluid bodies helps to elucidate their observed variability and the underlying physical mechanisms. Indeed, global oscillations and bending modes of accretion discs or tori may be relevant to quasi-periodicity and warped structures around compact objects. While most studies rely on linear theory, observationally significant, non-linear dynamics is still poorly understood, especially in Keplerian discs for which resonances typically demand a separate treatment. In this work, we introduce a novel analytical model which exactly solves the ideal, compressible fluid equations for a non-self-gravitating elliptical cylinder within a local shearing sheet. The aspect ratio of the ring is an adjustable parameter, allowing a continuum of models ranging from a torus of circular cross-section to a thin ring. We restrict attention to flow fields which are a linear function of the coordinates, capturing the lowest order global motions and reducing the dynamics to a set of coupled ordinary differential equations (ODEs). This system acts as a framework for exploring a rich range of hydrodynamic phenomena in both the large amplitude and Keplerian regimes. We demonstrate the connection between tilting tori and warped discs within this model, showing that the linear modes of the ring correspond to oppositely precessing global bending modes. These are further confirmed within a numerical grid based simulation. Crucially, the ODE system developed here allows for a more tractable investigation of non-linear dynamics. This will be demonstrated in a subsequent paper which evidences mode coupling between warping and vertical motions in thin tilted rings.
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DoAr 44 T Tauri 过渡盘中的内扭曲
影响因子：
4.8
作者：
S. Casassus;H. Avenhaus;S. Pérez;Victor Navarro;M. Cárcamo;S. Marino;L. Cieza;S. Quanz;Felipe Alarcón;A. Zurlo;A. Osses;F. R. Rannou;Pablo E. Romaan;M. Barraza
通讯作者：
M. Barraza
影响因子：
56.9
作者：
S. Kraus;A. Kreplin;Alison K. Young;M. Bate;J. Monnier;T. Harries;H. Avenhaus;J. Kluska;A. Laws
通讯作者：
S. Kraus;A. Kreplin;Alison K. Young;M. Bate;J. Monnier;T. Harries;H. Avenhaus;J. Kluska;A. Laws
影响因子：
4.8
作者：
J. Goodman;R. Narayan;P. Goldreich
通讯作者：
P. Goldreich
天体物理圆盘动力学的仿射模型
影响因子：
4.8
作者：
G. Ogilvie
通讯作者：
G. Ogilvie
TW Hya DISK 内部区域 CO 气体的运动学
DOI：
10.1088/0004-637x/757/2/129
发表时间：
2012
期刊：
The Astrophysical Journal
影响因子：
--
作者：
K. Rosenfeld;C. Qi;S. Andrews;D. Wilner;S. Corder;C. Dullemond;Shin;A. Hughes;P. D’Alessio;P. Ho
通讯作者：
P. Ho