论文标题
用小规模的AGN风能为银河系提供动力
Powering galactic super-winds with small-scale AGN winds
论文作者
论文摘要
我们提出了一种新的实施，用于通过运动网格流体动力密码中的小规模的超快速风，用于主动银河核（AGN）反馈。风是通过根据积聚盘风的可用约束来注入质量，动量和能量通量，以超级质量黑洞的为中心。在扫除与自己的小规模风能相等的质量之后，以动态，结构和冷却性能为能量驱动的流出提供了与分析风解决方案相吻合的。动量驱动的溶液并不容易发生，因为康普顿冷却半径通常比小规模风的自由膨胀半径小得多。通过各种收敛测试，我们证明了我们的实施产生的风解决方案，这些解决方案已充分融合到宇宙学模拟中实现的典型分辨率。我们在分离的银河系 - 质量星系的流体动力模拟中测试我们的模型。在关键的AGN亮度上方，最初是球形的，小规模的风能双极性，能量驱动的超级风，从银河核中断出来，以$> 1000 \ rm \，km \，km \，km \，s^{ - 1} $流到$> 1000 \ rm \，to $ \ sim \ sim \ sim \ sim \ rm kpc kpc $。这些能量驱动的流出导致恒星形成中等但长期的减少，这对于更高的AGN发光性和更快的小规模风变得更加明显。恒星形成的抑制是通过快速模式进行的，该模式涉及去除最高密度，核气和通过有效停止晕气气体积聚的较慢模式。我们的新实现使得在模拟星系演化，星际介质和黑洞积聚的模拟中以物理有意义且经过验证的方式对AGN驱动的风进行建模。
We present a new implementation for active galactic nucleus (AGN) feedback through small-scale, ultra-fast winds in the moving-mesh hydrodynamic code AREPO. The wind is injected by prescribing mass, momentum and energy fluxes across a spherical boundary centred on a supermassive black hole according to available constraints for accretion disc winds. After sweeping-up a mass equal to their own, small-scale winds thermalise, powering energy-driven outflows with dynamics, structure and cooling properties in excellent agreement with those of analytic wind solutions. Momentum-driven solutions do not easily occur, because the Compton cooling radius is usually much smaller than the free-expansion radius of the small-scale winds. Through various convergence tests, we demonstrate that our implementation yields wind solutions which are well converged down to the typical resolution achieved in cosmological simulations. We test our model in hydrodynamic simulations of isolated Milky Way - mass galaxies. Above a critical AGN luminosity, initially spherical, small-scale winds power bipolar, energy-driven super-winds that break out of the galactic nucleus, flowing at speeds $> 1000 \rm \, km \, s^{-1}$ out to $\sim 10 \, \rm kpc$. These energy-driven outflows result in moderate, but long-term, reduction in star formation, which becomes more pronounced for higher AGN luminosities and faster small-scale winds. Suppression of star formation proceeds through a rapid mode that involves the removal of the highest-density, nuclear gas and through a slower mode that effectively halts halo gas accretion. Our new implementation makes it possible to model AGN-driven winds in a physically meaningful and validated way in simulations of galaxy evolution, the interstellar medium and black hole accretion flows.
