垂直摆动吸积盘中的不稳定性和扭曲

Loren E. Held, Gordon I. Ogilvie
{"title":"垂直摆动吸积盘中的不稳定性和扭曲","authors":"Loren E. Held, Gordon I. Ogilvie","doi":"arxiv-2409.11490","DOIUrl":null,"url":null,"abstract":"Many accretion discs have been found to be distorted: either warped due a\nmisalignment in the system, or non-circular as a result of orbital eccentricity\nor tidal deformation by a binary companion. Warped, eccentric, and tidally\ndistorted discs are not in vertical hydrostatic equilibrium, and thus exhibit\nvertical oscillations in the direction perpendicular to the disc, a phenomenon\nthat is absent in circular and flat discs. In extreme cases, this vertical\nmotion is manifested as a vertical `bouncing' of the gas, potentially leading\nto shocks and heating, as observed in recent global numerical simulations. In\nthis paper we isolate the mechanics of vertical disc oscillations by means of\nquasi-2D and fully 3D hydrodynamic local (shearing-box) models. To determine\nthe numerical and physical dissipation mechanisms at work during an oscillation\nwe start by investigating unforced oscillations, examining the effect of\ninitial oscillation amplitude, as well as resolution, boundary conditions, and\nvertical box size on the dissipation and energetics of the oscillations. We\nthen drive the oscillations by introducing a time-dependent gravitational\npotential. A key result is that even a purely vertically oscillating disc is\n(parametrically) unstable to developing inertial waves, as we confirm through a\nlinear stability analysis. The most important of these has the character of a\nbending wave, whose radial wavelength depends on the frequency of the vertical\noscillation. The nonlinear phase of the instability exhibits shocks, which\ndampen the oscillations, although energy can also flow from the bending wave\nback to the vertical oscillation.","PeriodicalId":501068,"journal":{"name":"arXiv - PHYS - Solar and Stellar Astrophysics","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Instability and warping in vertically oscillating accretion discs\",\"authors\":\"Loren E. Held, Gordon I. Ogilvie\",\"doi\":\"arxiv-2409.11490\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Many accretion discs have been found to be distorted: either warped due a\\nmisalignment in the system, or non-circular as a result of orbital eccentricity\\nor tidal deformation by a binary companion. Warped, eccentric, and tidally\\ndistorted discs are not in vertical hydrostatic equilibrium, and thus exhibit\\nvertical oscillations in the direction perpendicular to the disc, a phenomenon\\nthat is absent in circular and flat discs. In extreme cases, this vertical\\nmotion is manifested as a vertical `bouncing' of the gas, potentially leading\\nto shocks and heating, as observed in recent global numerical simulations. In\\nthis paper we isolate the mechanics of vertical disc oscillations by means of\\nquasi-2D and fully 3D hydrodynamic local (shearing-box) models. To determine\\nthe numerical and physical dissipation mechanisms at work during an oscillation\\nwe start by investigating unforced oscillations, examining the effect of\\ninitial oscillation amplitude, as well as resolution, boundary conditions, and\\nvertical box size on the dissipation and energetics of the oscillations. We\\nthen drive the oscillations by introducing a time-dependent gravitational\\npotential. A key result is that even a purely vertically oscillating disc is\\n(parametrically) unstable to developing inertial waves, as we confirm through a\\nlinear stability analysis. The most important of these has the character of a\\nbending wave, whose radial wavelength depends on the frequency of the vertical\\noscillation. The nonlinear phase of the instability exhibits shocks, which\\ndampen the oscillations, although energy can also flow from the bending wave\\nback to the vertical oscillation.\",\"PeriodicalId\":501068,\"journal\":{\"name\":\"arXiv - PHYS - Solar and Stellar Astrophysics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-09-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Solar and Stellar Astrophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2409.11490\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Solar and Stellar Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.11490","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

摘要

许多吸积盘都被发现是扭曲的:或者由于系统中的偏差而扭曲,或者由于轨道偏心或双星伴星的潮汐变形而非圆形。翘曲、偏心和潮汐变形的圆盘并不处于垂直流体静力学平衡状态,因此会在垂直于圆盘的方向上出现垂直振荡,这种现象在圆形和平面圆盘中是不存在的。在极端情况下,这种垂直运动表现为气体的垂直 "弹跳",有可能导致冲击和加热,这在最近的全局数值模拟中也观察到了。在本文中,我们通过准二维和全三维流体力学局部(剪切盒)模型,分离出垂直圆盘振荡的力学原理。为了确定振荡期间起作用的数值和物理耗散机制,我们首先研究了非受迫振荡,考察了初始振荡振幅、分辨率、边界条件和垂直箱尺寸对振荡耗散和能量的影响。Wethen 通过引入随时间变化的引力势来驱动振荡。一个关键结果是,我们通过线性稳定性分析证实,即使是一个纯粹垂直振荡的圆盘,在发展惯性波时(参数上)也是不稳定的。其中最重要的惯性波具有弯曲波的特征,其径向波长取决于垂直振荡的频率。不稳定性的非线性阶段会出现冲击,从而减弱振荡,尽管能量也会从弯曲波流回垂直振荡。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Instability and warping in vertically oscillating accretion discs
Many accretion discs have been found to be distorted: either warped due a misalignment in the system, or non-circular as a result of orbital eccentricity or tidal deformation by a binary companion. Warped, eccentric, and tidally distorted discs are not in vertical hydrostatic equilibrium, and thus exhibit vertical oscillations in the direction perpendicular to the disc, a phenomenon that is absent in circular and flat discs. In extreme cases, this vertical motion is manifested as a vertical `bouncing' of the gas, potentially leading to shocks and heating, as observed in recent global numerical simulations. In this paper we isolate the mechanics of vertical disc oscillations by means of quasi-2D and fully 3D hydrodynamic local (shearing-box) models. To determine the numerical and physical dissipation mechanisms at work during an oscillation we start by investigating unforced oscillations, examining the effect of initial oscillation amplitude, as well as resolution, boundary conditions, and vertical box size on the dissipation and energetics of the oscillations. We then drive the oscillations by introducing a time-dependent gravitational potential. A key result is that even a purely vertically oscillating disc is (parametrically) unstable to developing inertial waves, as we confirm through a linear stability analysis. The most important of these has the character of a bending wave, whose radial wavelength depends on the frequency of the vertical oscillation. The nonlinear phase of the instability exhibits shocks, which dampen the oscillations, although energy can also flow from the bending wave back to the vertical oscillation.
求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信