Supermassive black holes in cosmological simulations - II: the AGN population and predictions for upcoming X-ray missions
Supermassive black holes in cosmological simulations - II: the AGN population and predictions for upcoming X-ray missions
复制标题
宇宙学模拟中的超大质量黑洞 - II：活动星系核数量和对即将到来的 X 射线任务的预测
DOI：
10.1093/mnras/stab3147
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发表时间：
2022
影响因子：
4.8
通讯作者：
Habouzit M
中科院分区：
文献类型：
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作者：
Habouzit M
在大尺度流体动力学宇宙学模拟中，大质量星系的命运主要取决于对活动星系核（agn）反馈的建模。AGN反馈释放的能量与被吸积到黑洞（BHs）上的质量成正比，但AGN反馈的精确子网格模型在所有模拟中都是不同的。虽然现代模拟可靠地产生了atz≤2的静止大质量星系群，但评估AGN群的相似性和差异性也至关重要。在这里，我们比较了Illustris、TNG100、TNG300、Horizon-AGN、EAGLE和SIMBA模拟的AGN种群。在不同的模拟中，AGN的亮度函数（LF）变化很大。虽然与当前的观测约束atz= 0一致，但在较高的红移下，由于大多数模拟产生了太多的agn， LFs的一致性就变差了。在一些模拟中，AGN反馈阻止了任何明亮的AGN的存在（尽管这对AGN的可变性很敏感），并导致在大质量星系中AGN的比例比在atz≤2的观测中要小。我们发现，所有的模拟都不能产生与观测约束很好地一致的AGN密度，无论是明亮的（）还是暗淡的（）AGN，以及低红移和高红移。这些差异可以帮助我们改进未来的黑洞和星系亚网格模拟。即将到来的x射线任务（如雅典娜、AXIS和LynX）将带来微弱的agn和新的强大约束。在考虑到AGN遮挡后，我们发现，在任何红移情况下，未来调查中可探测AGN的预测数量密度至少跨越了模拟的一个数量级。
In large-scale hydrodynamical cosmological simulations, the fate of massive galaxies is mainly dictated by the modelling of feedback from active galactic nuclei (AGNs). The amount of energy released by AGN feedback is proportional to the mass that has been accreted on to the black holes (BHs), but the exact subgrid modelling of AGN feedback differs in all simulations. While modern simulations reliably produce populations of quiescent massive galaxies atz≤ 2, it is also crucial to assess the similarities and differences of the responsible AGN populations. Here, we compare the AGN populations of the Illustris, TNG100, TNG300, Horizon-AGN, EAGLE, and SIMBA simulations. The AGN luminosity function (LF) varies significantly between simulations. Although in agreement with current observational constraints atz= 0, at higher redshift the agreement of the LFs deteriorates with most simulations producing too many AGNs of. AGN feedback in some simulations prevents the existence of any bright AGN with(although this is sensitive to AGN variability), and leads to smaller fractions of AGN in massive galaxies than in the observations atz≤ 2. We find that all the simulations fail at producing a number density of AGN in good agreement with observational constraints for both luminous () and fainter () AGNs and at both low and high redshifts. These differences can aid us in improving future BH and galaxy subgrid modelling in simulations. Upcoming X-ray missions (e.g. Athena, AXIS, and LynX) will bring faint AGNs to light and new powerful constraints. After accounting for AGN obscuration, we find that the predicted number density of detectable AGNs in future surveys spans at least one order of magnitude across the simulations, at any redshift.