Galaxy-scale outflows driven by active galactic nuclei
Galaxy-scale outflows driven by active galactic nuclei
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活跃星系核驱动的星系尺度外流
DOI：
10.1111/j.1365-2966.2011.20187.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
Chung
中科院分区：
文献类型：
--
作者：
J. DeBuhr;E. Quataert;Chung
我们给出了主要星系合并的流体力学模拟，并研究了活动星系核(AGN)产生的风对AGN所在星系星际气体的影响。我们考虑初始风速为∼10000公里的S−1，初始动量(能量)通量为∼τw L/c(∼0.01nτw t L)，其中。活动星系核的风卷起并激波加热周围的星际气体，导致了一场星系规模的外流，速度为∼，距离S−1 1000公里，峰值质量外流速率与恒星形成速率相当，总抛射气体质量为∼3×109fM⊙。由活动星系核驱动的星系外流需要大的动量通量τw≳3来抑制黑洞宿主星系中恒星的形成和吸积。威力较小的活动星系核风(τw≲3)仍然会产生适度的星系规模的外流，但这种外流对周围的星际气体几乎没有全球影响。我们认为，这种活动星系核反馈机制可能会产生在恒星爆发后星系中观察到的高速流出，以及在局部超明亮红外星系中观察到的大量分子和原子流出。此外，从局部超高亮度红外星系流出的τw∼10，与我们发现的调节黑洞生长和建立MBH-σ关系所需的活动星系核的风相媲美。我们最后讨论了导致活动星系核、风质量负荷和动量/能量通量大到足以对星系形成产生重大影响的理论机制。
We present hydrodynamical simulations of major mergers of galaxies and study the effects of winds produced by active galactic nuclei (AGN) on interstellar gas in the AGN’s host galaxy. We consider winds with initial velocities ∼10 000 km s−1 and an initial momentum (energy) flux of ∼τw L/c (∼ 0.01 τw L), with . The AGN wind sweeps up and shock heats the surrounding interstellar gas, leading to a galaxy-scale outflow with velocities ∼1000 km s−1, peak mass outflow rates comparable to the star formation rate and a total ejected gas mass of ∼3 × 109 M⊙. Large momentum fluxes, τw≳ 3, are required for the AGN-driven galactic outflow to suppress star formation and accretion in the black hole’s host galaxy. Less powerful AGN winds (τw≲ 3) still produce a modest galaxy-scale outflow, but the outflow has little global effect on the ambient interstellar gas. We argue that this mechanism of AGN feedback can plausibly produce the high-velocity outflows observed in post-starburst galaxies and the massive molecular and atomic outflows observed in local ultraluminous infrared galaxies. Moreover, the outflows from local ultraluminous infrared galaxies are inferred to have τw∼ 10, comparable to what we find is required for AGN winds to regulate the growth of black holes and set the MBH - σ relation. We conclude by discussing theoretical mechanisms that can lead to AGN wind mass loading and momentum/energy fluxes large enough to have a significant impact on galaxy formation.