Quantifying AGN-driven metal-enhanced outflows in chemodynamical simulations
Quantifying AGN-driven metal-enhanced outflows in chemodynamical simulations
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在化学动力学模拟中量化 AGN 驱动的金属增强流出
DOI：
10.1093/mnrasl/slv087
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发表时间：
2015
影响因子：
4.8
通讯作者：
C. Kobayashi
中科院分区：
文献类型：
--
作者：
P. Taylor;C. Kobayashi
我们展示了agn驱动的流出物对重元素喷射的影响，使用我们的宇宙学模拟，超大质量黑洞起源于第一批恒星。在大多数大质量星系中，我们已经确定了两种明显由AGN反馈驱动的强烈外流。这些流出物在AGN附近的速度大于$ $ 8000$ km\,s$ $^{-1}$，并以$ $ 3000$ km\,s$ $^{-1}$的速度向外传播到半个Mpc。这些流出物从宿主星系带走了剩余的气体（重子的3%）和大量的金属（总产生金属的2%），在化学上丰富了环星系介质（CGM）和星系间介质（IGM）。这个星系中17.6%的金属和模拟中18.4%的金属最终分别进入了CGM和IGM。在AGN反馈下，CGM和IGM的金属丰度较高，而星系的质量-金属丰度关系没有受到太大影响。我们还发现，由于Ia型超新星的时间延迟，铁比氧更有效地喷射出“选择性”质量损失。agn驱动的外流不仅在大质量星系的恒星形成淬火中发挥重要作用，以匹配观测到的缩小现象，而且在宇宙中大规模的化学富集中发挥重要作用。流出物中金属丰度和元素丰度比的观测约束对于验证星系形成中AGN反馈的建模是重要的。
We show the effects of AGN-driven outflows on the ejection of heavy elements using our cosmological simulations, where super-massive black holes originate from the first stars. In the most massive galaxy, we have identified two strong outflows unambiguously driven by AGN feedback. These outflows have a speed greater than $\sim 8000$ km\,s$^{-1}$ near the AGN, and travel out to a half Mpc with $\sim 3000$ km\,s$^{-1}$. These outflows remove the remaining gas ($\sim 3$ per cent of baryons) and significant amounts of metals ($\sim 2$ per cent of total produced metals) from the host galaxy, chemically enriching the circumgalactic medium (CGM) and the intergalactic medium (IGM). 17.6 per cent of metals from this galaxy, and 18.4 per cent of total produced metals in the simulation, end up in the CGM and IGM, respectively. The metallicities of the CGM and IGM are higher with AGN feedback, while the mass--metallicity relation of galaxies is not affected very much. We also find `selective' mass-loss where iron is more effectively ejected than oxygen because of the time-delay of Type Ia Supernovae. AGN-driven outflows play an essential role not only in quenching of star formation in massive galaxies to match with observed down-sizing phenomena, but also in a large-scale chemical enrichment in the Universe. Observational constraints of metallicities and elemental abundance ratios in outflows are important to test the modelling of AGN feedback in galaxy formation.
半人马座北部中射电瓣中的喷射加热 X 射线细丝
DOI：
10.1088/0004-637x/698/2/2036
发表时间：
2009
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Kraft R
通讯作者：
Kraft R