Structure of the super-Eddington outflow and its impact on the cosmological scale
Structure of the super-Eddington outflow and its impact on the cosmological scale
复制标题
超爱丁顿外流的结构及其对宇宙尺度的影响
DOI：
10.1093/pasj/psac001
复制
发表时间：
2022
影响因子：
2.3
通讯作者：
Kawashima Tomohisa
中科院分区：
文献类型：
--
作者：
Botella Ignacio;Mineshige Shin;Kitaki Takaaki;Ohsuga Ken;Kawashima Tomohisa
如何准确地评价黑洞对环境的反馈是黑洞天体物理学研究中的一个重要问题。为了研究高红移下超大质量黑洞（SMBH）种子周围的超爱丁顿流的独特气体动力学性质，采用嵌套模拟盒方法对SMBH种子周围的超爱丁顿流进行了轴对称二维辐射流体动力学模拟.在这里，我们将模拟箱分为一个内部区域在（2-3 × 103）rSch（其中rSchwarzschild半径）和一个外部区域在（2 × 103-3 × 106）rSch，与平滑连接的物理量，如气体密度，速度和辐射能量。我们开始计算时，以恒定的速率通过内区的外边界注入质量，其中LEdd是爱丁顿光度，是光速。一个强大的外流产生在最里面的区域，它从内部区域传播到外部区域。外流的特征是速度为0.02 c（0.7 c），密度为10−17（10−19）g cm− 3，接近边缘（正面）方向。流出物在受到辐射压力的作用时逐渐加速。最外边界处的最终质量流出速率为。将外流结构外推到更大的尺度上，我们发现在τ = 0.1pc处的动量通量和能量通量分别为τ 10- 100 LEdd/c和τ 0.1- 10 LEdd。此外，我们发现的影响是高度各向异性的，在这个意义上说，更大的影响发生在面对的方向比在边缘上的方向。这些结果表明，BH反馈将更有效地工作在星际介质中比假设在宇宙学模拟。
It is one of the biggest issues in black hole (BH) astrophysics how to evaluate BH feedback to its environments precisely. Aiming at studying the unique gas dynamics of super-Eddington flow around supermassive black hole (SMBH) seeds at high redshift, we carried out axisymmetric two-dimensional radiation hydrodynamic simulations using a nested simulation-box method. Here we divide the simulation box into an inner zone at (2–3 × 103)rSch(withrSchbeing the Schwarzschild radius) and an outer zone at (2 × 103–3 × 106)rSch, with smooth connection of the physical quantities, such as gas density, velocity, and radiation energy. We start the calculation by injecting mass through the outer boundary of the inner zone at a constant rate of, whereLEddis the Eddington luminosity andcis the speed of light. A powerful outflow is generated in the innermost region and it propagates from the inner zone to the outer zone. The outflows are characterized by a velocity of 0.02c(0.7c) and density of 10−17(10−19) g cm−3for near the edge-on (face-on) direction. The outflow is gradually accelerated as it travels by accepting radiation-pressure force. The final mass outflow rate at the outermost boundary is. By extrapolating the outflow structure to a further larger scale, we find that the momentum and energy fluxes atr∼ 0.1 pc are ∼10–100LEdd/cand ∼0.1–10LEdd, respectively. Moreover, we find that the impacts are highly anisotropic, in the sense that larger impacts occur towards the face-on direction than in the edge-on direction. These results indicate that the BH feedback will work more efficiently on the interstellar medium than assumed in the cosmological simulations.