Radiation drag effects in black hole outflows from super-critical accretion disks via special relativistic radiation magnetohydrodynamics simulations
Radiation drag effects in black hole outflows from super-critical accretion disks via special relativistic radiation magnetohydrodynamics simulations
复制标题
通过特殊相对论辐射磁流体动力学模拟，超临界吸积盘黑洞流出的辐射阻力效应
DOI：
10.1093/pasj/psu145
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发表时间：
2015
影响因子：
2.3
通讯作者：
Ken
中科院分区：
文献类型：
--
作者：
Takahashi;Hiroyuki R.; Ohsuga;Ken
通过2.5维特殊相对论辐射磁流体动力学模拟，我们研究了超临界吸积盘和通过辐射力启动的外流。结果表明，辐射通量对外流有加速作用，但辐射阻力阻碍了外流速度的增加。流出速度约为绕旋转轴的光速的30%-40%，因为此后磁通力与阻力平衡。我们的模拟表明，流出速度在10^{2-3}L{\rm Edd}/c^{\，2}$范围内几乎保持不变，其中$skew4\点{M}_{\rm BH}$是质量吸积率，LEddd是爱丁顿光度，c1是光速。这种较快的流出被较慢的流出∼ 0.1c所包围。这个速度也是由辐射通量力和辐射阻力之间的平衡决定的。辐射阻力与洛伦兹力共同作用来准直较慢的外流，尽管较快的外流主要由洛伦兹力来准直。动能是由较慢的流出而不是较快的流出携带的。流出的总动力学光度和光子光度几乎与质量吸积率无关，均为∼。
By performing 2.5-dimensional special relativistic radiation magnetohydrodynamics simulations, we study super-critical accretion disks and the outflows launched via the radiation force. We find that the outflow is accelerated by the radiation flux force, but the radiation drag force prevents the outflow velocity from increasing. The outflow velocity saturates around 30%–40% of the light speed around the rotation axis, since then the flux force balances with the drag force. Our simulations show that the outflow velocity is kept nearly constant in the region of $\skew4\dot{M}_{\rm BH}\sim 10^{2-3}L_{\rm Edd}/c^{\,2}$, where $\skew4\dot{M}_{\rm BH}$ is the mass accretion rate,LEddis the Eddington luminosity, andcis the light speed. Such a faster outflow is surrounded by a slower outflow of ∼ 0.1c. This velocity is also determined by the balance between the radiation flux force and the radiation drag. The radiation drag works to collimate the slower outflow in cooperation with the Lorentz force, although the faster outflow is mainly collimated by the Lorentz force. The kinetic energy is carried by the slower outflow rather than by the faster outflow. The total kinetic luminosity of the outflow as well as the photon luminosity is ∼LEdd, almost independent of the mass accretion rate.