论文标题

辐射传输的两个温度GRMHD模拟的翘曲磁盘

Radiation Transport Two-Temperature GRMHD Simulations of Warped Accretion Disks

论文作者

Liska, M. T. P., Kaaz, N., Musoke, G., Tchekhovskoy, A., Porth, O.

论文摘要

在许多黑洞系统中,预计相对于黑洞旋转轴未对准积聚磁盘。如果磁盘的尺度高于未对准角度的高度,则黑洞的旋转可以将磁盘撕成多个,独立进攻的“子盘”。这最有可能在黑洞X射线二进制文件(BHXRB)和积极的银河核(AGN)中爆发中发生,因为磁盘变成了剃须刀,因此产生了高于Eddington限制的百分之几百分之几。磁盘撕裂具有解释可变性现象的潜力,包括BHXRB中的准周期振荡(QPO)和AGN中的更换现象。在这里,我们介绍了一个强烈的倾斜($ 65^{\ circ} $)积聚盘的第一个辐射两倍的GRMHD仿真,周围是$ M_ {BH} = 10M _ {\ odot} $ Black Hole,撕裂和预言。这导致亮度波动在次级时间尺度的Eddington限制的几%至50美元之间。令人惊讶的是,即使磁盘是辐射压力主导的,也可以在$ t \ gtrsim 21,000 r_g/c $上进行热稳定。这表明WARPS在稳定磁盘防止热塌陷方面起着重要作用。磁盘形成垂直于节点线的两个喷嘴冲击,其中磁盘的比例高度降低了$ 10 $倍,电子温度达到$ t_e \ sim \ sim 10^8-10^9 k $。此外,将内部和外磁盘之间的撕裂的光学稀薄气体加热到$ t_e \ sim 10^8 k $。这表明扭曲的磁盘可能会散发出一个构成的频谱,该光谱与理想化的模型大大偏离。

In many black hole systems, the accretion disk is expected to be misaligned with respect to the black hole spin axis. If the scale height of the disk is much smaller than the misalignment angle, the spin of the black hole can tear the disk into multiple, independently precessing `sub-disks'. This is most likely to happen during outbursts in black hole X-Ray binaries (BHXRBs) and in active galactic nuclei (AGN) accreting above a few percent of the Eddington limit, because the disk becomes razor-thin. Disk tearing has the potential to explain variability phenomena including quasi-periodic oscillations (QPOs) in BHXRBs and changing-look phenomena in AGN. Here, we present the first radiative two-temperature GRMHD simulation of a strongly tilted ($65^{\circ}$) accretion disk around a $M_{BH}=10M_{\odot}$ black hole, which tears and precesses. This leads to luminosity swings between a few percent and $50 \%$ of the Eddington limit on sub-viscous timescales. Surprisingly, even where the disk is radiation pressure dominated, the accretion disk is thermally stable over $t \gtrsim 21,000 r_g/c$. This suggests warps play an important role in stabilizing the disk against thermal collapse. The disk forms two nozzle shocks perpendicular to the line of nodes where the scale height of the disk decreases $10$-fold and the electron temperature reaches $T_e \sim 10^8-10^9 K$. In addition, optically thin gas crossing the tear between the inner and outer disk gets heated to $T_e \sim 10^8 K$. This suggests that warped disks may emit a Comptonized spectrum that deviates substantially from idealized models.

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