论文标题
气体在活跃的银河核中流动。 I.两相气体流入
Gas flows in an Active galactic nuclei. I. Two-phase gas inflow
论文作者
论文摘要
我们执行二维流体动力模拟，研究该地区的1-1000 PARSEC区域的非旋转气流。该区域连接星系尺度和积聚磁盘量表。气体由中央黑洞附近的积聚磁盘系统产生的光子辐射，其$ 10^8 $太阳质量。我们假设中央吸积系统的发光度是恒定的，等于$ 0.3 $ Eddington的发光度。密度高于$ 10^{ - 24} {\ rm g \ cm^{ - 3}} $的气体是热不稳定的。由于热不稳定性，两相，冷和热的气流将形成。我们计算了冷气吸积率与热气体积聚率的比率。该比率是气体密度的函数，通常随着气体密度的增加而增加。当气体密度为$ 10^{ - 21} {\ rm g \ cm^{ - 3}} $时，该比率的最大值为$ 16 $。密度低于$ 10^{ - 24} {\ rm g \ cm^{ - 3}} $的气体被发现是热稳定的，并且气流是一相的。简要讨论结果的应用。
We perform two-dimensional hydrodynamic simulations to study the non-rotating gas flow in the region from 1-1000 parsec. This region connects the galaxy scale and the accretion disk scale. The gas is irradiated by the photons generated by the accretion disk system near the central black hole with $10^8$ solar mass. We assume that the luminosity of the central accretion system is constant and equals to $0.3$ Eddington luminosity. Gas with density higher than $10^{-24} {\rm g \ cm^{-3}}$ is found to be thermally unstable. Two phase, cold and hot, gas flow will form due to thermal instability. We calculated the ratio of cold gas accretion rate to hot gas accretion rate. This ratio is a function of gas density and generally increases with the increase of gas density. The maximum value of this ratio is $16$, when gas density is $10^{-21} {\rm g \ cm^{-3}} $. Gas with density lower than $10^{-24} {\rm g \ cm^{-3}}$ is found to be thermally stable and the gas flow is one-phase. The applications of the results are briefly discussed.
