PARSEC-SCALE ACCRETION AND WINDS IRRADIATED BY A QUASAR
PARSEC-SCALE ACCRETION AND WINDS IRRADIATED BY A QUASAR
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DOI：
10.3847/0004-637x/819/2/115
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
A. Dorodnitsyn;T. Kallman;D. Proga
中科院分区：
文献类型：
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作者：
A. Dorodnitsyn;T. Kallman;D. Proga
本文对活动星系核（AGN）中央黑洞照射下的秒差距尺度环面的性质进行了数值模拟。我们的物理模型可以同时研究风的形成和吸积之间的平衡。考虑到紫外线和红外线辐射沿着X射线加热和尘埃升华产生的辐射压力，允许产生辐射驱动风。通过角动量传输和辐射、粘性辐射流体动力学方程的解允许吸积。我们的方法采用通量限制扩散辐射流体动力学的尘埃，红外压力驱动的流动的一部分，沿着与X射线加热和冷却。角动量输运的吸积部分的流量建模使用有效粘度。我们的研究结果表明，尘埃辐射压力可以发挥重要的作用，在塑造活动星系核遮蔽。例如，当照亮环面的光度超过L > 0.01 L Edd？>，其中LEdd是爱丁顿光度，我们没有发现持续的磁盘吸积的插曲，因为辐射压力不允许磁盘的形成。尽管没有吸积盘，气体向较小半径的流动仍然以10 - 4-10 - 1 M·yr-1？通过捕获来自热蒸发流的气体，从而提供将气体从辐射压力主导的环面输送到内部吸积盘的机制。作为L / L edd？>增加，更大的辐射输入导致更大的环面纵横比和中心黑洞的遮蔽增加。我们还发现了X射线加热的气体在形成模糊环面的重要作用。
We present numerical simulations of properties of a parsec-scale torus exposed to illumination by the central black hole in an active galactic nucleus (AGN). Our physical model allows to investigate the balance between the formation of winds and accretion simultaneously. Radiation-driven winds are allowed by taking into account radiation pressure due to UV and IR radiation along with X-ray heating and dust sublimation. Accretion is allowed through angular momentum transport and the solution of the equations of radiative, viscous radiation hydrodynamics. Our methods adopt flux-limited diffusion radiation hydrodynamics for the dusty, infrared pressure driven part of the flow, along with X-ray heating and cooling. Angular momentum transport in the accreting part of the flow is modeled using effective viscosity. Our results demonstrate that radiation pressure on dust can play an important role in shaping AGN obscuration. For example, when the luminosity illuminating the torus exceeds L > 0.01 L Edd ?> , where LEdd is the Eddington luminosity, we find no episodes of sustained disk accretion because radiation pressure does not allow a disk to form. Despite the absence of the disk accretion, the flow of gas to smaller radii still proceeds at a rate 10−4–10−1 M ⊙ yr − 1 ?> through the capturing of the gas from the hot evaporative flow, thus providing a mechanism to deliver gas from a radiation–pressure dominated torus to the inner accretion disk. As L / L edd ?> increases, larger radiation input leads to larger torus aspect ratios and increased obscuration of the central black hole. We also find the important role of the X-ray heated gas in shaping the obscuring torus.