Radiation hydrodynamics simulations of line-driven AGN disc winds: metallicity dependence and black hole growth
Radiation hydrodynamics simulations of line-driven AGN disc winds: metallicity dependence and black hole growth
复制标题
线驱动 AGN 盘风的辐射流体动力学模拟：金属丰度依赖性和黑洞生长
DOI：
10.1093/mnras/stab2214
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发表时间：
2021
影响因子：
4.8
通讯作者：
Ohsuga Ken
中科院分区：
文献类型：
--
作者：
Nomura Mariko;Omukai Kazuyuki;Ohsuga Ken
黑洞（BHs）从种子到超大质量黑洞（SMBHs）的成长尚不清楚，但质量吸积肯定起了重要作用。考虑到在大范围的黑洞质量中金属丰度的依赖性，我们对线驱动圆盘风进行了二维辐射流体动力学模拟，并研究了由于风的质量损失而导致的质量吸积率的降低。我们的结果表明，密度更高、速度更快的盘状风出现在更高的金属丰度和更大的黑洞质量上。在Z≥Z⊙的高金属丰度环境中，BH质量的吸积率被抑制到质量供给率的~ 0.4-0.6倍，而当金属丰度低于太阳（~ 0.1Z⊙）时，风的质量损失可以忽略不计。通过建立半解析模型，我们发现线力的金属丰度依赖性和风发射区表面积的黑洞质量依赖性是质量损失率的金属丰度依赖性（∝Z2/3）和黑洞质量依赖性（forand∝MBHfor）的原因。我们的模型表明，在富含金属的环境中，通过气体吸积形成的黑洞在> 105M⊙的状态下有效地减缓了生长。这意味着线驱动的盘状风可能对SMBHs的后期演化有影响。
Growth of the black holes (BHs) from the seeds to supermassive BHs (SMBHs,) is not understood, but the mass accretion must have played an important role. We performed 2D radiation hydrodynamics simulations of line-driven disc winds considering the metallicity dependence in a wide range of the BH mass, and investigated the reduction of the mass accretion rate due to the wind mass-loss. Our results show that denser and faster disc winds appear at higher metallicities and larger BH masses. The accretion rate is suppressed to ∼0.4–0.6 times the mass supply rate to the disc for the BH mass ofin high-metallicity environments ofZ≳Z⊙, while the wind mass-loss is negligible when the metallicity is subsolar (∼0.1Z⊙). By developing a semi-analytical model, we found that the metallicity dependence of the line force and the BH mass dependence of the surface area of the wind launch region are the cause of the metallicity dependence (∝Z2/3) and BH mass dependencies (forand ∝MBHfor) of the mass-loss rate. Our model suggests that the growth of BHs by the gas accretion effectively slows down in the regime ≳ 105M⊙in metal-enriched environments ≳Z⊙. This means that the line-driven disc winds may have an impact on late evolution of SMBHs.