Nozzle Shocks, Disk Tearing, and Streamers Drive Rapid Accretion in 3D GRMHD Simulations of Warped Thin Disks
Nozzle Shocks, Disk Tearing, and Streamers Drive Rapid Accretion in 3D GRMHD Simulations of Warped Thin Disks
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喷嘴冲击、圆盘撕裂和流光驱动翘曲薄圆盘 3D GRMHD 模拟中的快速吸积
DOI：
10.3847/1538-4357/ace051
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
O. Porth
中科院分区：
文献类型：
--
作者：
N. Kaaz;M. Liska;J. Jacquemin;Zachary L. Andalman;G. Musoke;A. Tchekhovskoy;O. Porth
供给黑洞（BH）的气体的角动量可能与BH自旋不一致，导致倾斜的吸积盘。黑洞的旋转会拖曳周围的时空，表现为导致盘旋进和翘曲的透镜-瑟林扭矩。我们研究这些过程，通过模拟薄（H/r = 0.02），高度倾斜（θ = 65 °）吸积盘周围的快速旋转（α = 0.9375）BH在极高的分辨率，我们使用广义相对论磁流体动力学代码H-AMR。这个盘变得明显扭曲，并不断撕裂成两个独立的旋进子盘。我们发现质量吸积率远远超过标准的α粘度预期。我们确定了两种新的耗散机制，具体到翘曲的磁盘是吸积的主要驱动程序，不同于通常被认为是驱动吸积的局部湍流应力。特别是，我们确定了极端的规模高度振荡，发生两次在我们的磁盘轨道。当天秤高度压缩时，"喷嘴"激波形成，耗散轨道能量并驱动吸积。除了这种现象，在撕裂的位置也有极端的耗散。这导致低角动量的"流光"的形成，这些流光落在内子盘上，使内子盘受到冲击。向内子盘添加低角动量的气体会使内子盘迅速吸积，即使它暂时与BH自旋对齐，因此没有翘曲。这些机制，如果普遍，显着修改标准的吸积范式。此外，它们可能在比α盘预期的更短的时间尺度上驱动结构变化，这可能解释了在活动星系核中观察到的一些极端变化。
The angular momentum of gas feeding a black hole (BH) may be misaligned with respect to the BH spin, resulting in a tilted accretion disk. Rotation of the BH drags the surrounding spacetime, manifesting as Lense–Thirring torques that lead to disk precession and warping. We study these processes by simulating a thin (H/r = 0.02), highly tilted ( =65° ) accretion disk around a rapidly rotating (a = 0.9375) BH at extremely high resolutions, which we performed using the general-relativistic magnetohydrodynamic code H-AMR. The disk becomes significantly warped and continuously tears into two individually precessing subdisks. We find that mass accretion rates far exceed the standard α-viscosity expectations. We identify two novel dissipation mechanisms specific to warped disks that are the main drivers of accretion, distinct from the local turbulent stresses that are usually thought to drive accretion. In particular, we identify extreme scale height oscillations that occur twice an orbit throughout our disk. When the scale height compresses, “nozzle” shocks form, dissipating orbital energy and driving accretion. Separate from this phenomenon, there is also extreme dissipation at the location of the tear. This leads to the formation of low-angular momentum “streamers” that rain down onto the inner subdisk, shocking it. The addition of low-angular momentum gas to the inner subdisk causes it to rapidly accrete, even when it is transiently aligned with the BH spin and thus unwarped. These mechanisms, if general, significantly modify the standard accretion paradigm. Additionally, they may drive structural changes on much shorter timescales than expected in α-disks, potentially explaining some of the extreme variability observed in active galactic nuclei.
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DOI：
10.3847/2041-8213/aab429
发表时间：
2018-03
期刊：
The Astrophysical Journal Letters
影响因子：
--
作者：
L. Dai;L. Dai;J. McKinney;Nathaniel Roth;E. Ramirez-Ruiz;E. Ramirez-Ruiz;M. Miller
通讯作者：
L. Dai;L. Dai;J. McKinney;Nathaniel Roth;E. Ramirez-Ruiz;E. Ramirez-Ruiz;M. Miller
影响因子：
4.8
作者：
M. Liska;M. Liska;C. Hesp;A. Tchekhovskoy;A. Ingram;M. Klis;S. Markoff;M. V. Moer
通讯作者：
M. Liska;M. Liska;C. Hesp;A. Tchekhovskoy;A. Ingram;M. Klis;S. Markoff;M. V. Moer
DOI：
10.3847/1538-4357/aaa9b6
发表时间：
2017-06
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Nick Rumbaugh;Yue Shen;E. Morganson;Xin Liu;M. Banerji;Richard G. McMahon;Filipe Abdalla;
通讯作者：
Nick Rumbaugh;Yue Shen;E. Morganson;Xin Liu;M. Banerji;Richard G. McMahon;Filipe Abdalla;
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
影响因子：
4.8
作者：
Fairbairn C
通讯作者：
Fairbairn C
非线性共振环面振荡作为开普勒圆盘扭曲动力学模型
影响因子：
4.8
作者：
Fairbairn C
通讯作者：
Fairbairn C