NO EVIDENCE FOR BARDEEN–PETTERSON ALIGNMENT IN GRMHD SIMULATIONS AND SEMI-ANALYTIC MODELS OF MODERATELY THIN, PROGRADE, TILTED ACCRETION DISKS
NO EVIDENCE FOR BARDEEN–PETTERSON ALIGNMENT IN GRMHD SIMULATIONS AND SEMI-ANALYTIC MODELS OF MODERATELY THIN, PROGRADE, TILTED ACCRETION DISKS
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在中等薄、渐进、倾斜吸积盘的 GRMHD 模拟和半解析模型中没有证据表明巴丁-彼得森对齐
DOI：
10.1088/0004-637x/796/2/104
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
D. M. Teixeira
中科院分区：
文献类型：
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作者：
V. Zhuravlev;P. Ivanov;P. C. Fragile;D. M. Teixeira
在这篇文章中，我们介绍了使用直接从数值模拟中提取的数据作为Zhuravlev&Ivanov的解析扭盘模型的输入的第一个结果。在数值和解析两种方法中，考虑了低速旋转Kerr黑洞周围具有中等有效粘性的倾斜和扭曲盘的完全相对论模型。定性上，分析模型表现出与模拟相同的动力学，尽管有一些定量的偏差。也就是说，一般的相对论磁流体力学模拟通常会给出较小的倾斜和扭转变化。当黑洞和圆盘同向旋转时，模拟的倾斜圆盘和解析模型没有显示出Bardeen-Petterson排列的迹象，即使在圆盘最内部，松弛到准静态位形的特征时间与计算时间相同的数量级。在相反的情况下，当圆盘的旋转方向与黑洞的旋转方向相反时，观察到部分排列，这与之前的理论估计一致。因此，无论是全数值格式还是解析格式都表明，在圆盘的有效粘性足够小的情况下，在进动旋转的情况下，Bardeen-Petterson效应可能是不可能的。这可能会对不同的天体物理现象，如圆盘光谱和喷流方向进行建模。
In this paper, we introduce the first results that use data extracted directly from numerical simulations as inputs to the analytic twisted disk model of Zhuravlev & Ivanov. In both numerical and analytic approaches, fully relativistic models of tilted and twisted disks having a moderate effective viscosity around a slowly rotating Kerr black hole are considered. Qualitatively, the analytic model demonstrates the same dynamics as the simulations, although with some quantitative offset. Namely, the general relativistic magnetohydrodynamic simulations typically give smaller variations of tilt and twist across the disk. When the black hole and the disk rotate in the same direction, the simulated tilted disk and analytic model show no sign of Bardeen–Petterson alignment, even in the innermost parts of the disk where the characteristic time for relaxation to a quasi-stationary configuration is of the same order as the computation time. In the opposite case, when the direction of the disk's rotation is opposite to that of the black hole, a partial alignment is observed, in agreement with previous theoretical estimates. Thus, both fully numerical and analytic schemes demonstrate that the Bardeen–Petterson effect may not be possible for the case of prograde rotation provided that disk's effective viscosity is sufficiently small. This may have implications in modeling of different astrophysical phenomena such as disk spectra and jet orientation.