The Accretion History of AGNs. I. Supermassive Black Hole Population Synthesis Model
The Accretion History of AGNs. I. Supermassive Black Hole Population Synthesis Model
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DOI：
10.3847/1538-4357/aafb77
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发表时间：
2018-10
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通讯作者：
Tonima Tasnim Ananna;E. Treister;C. Megan Urry;C. Ricci;A. Kirkpatrick;S. LaMassa;J. Buchner;F. Civano;M. Tremmel;S. Marchesi
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作者：
Tonima Tasnim Ananna;E. Treister;C. Megan Urry;C. Ricci;A. Kirkpatrick;S. LaMassa;J. Buchner;F. Civano;M. Tremmel;S. Marchesi
当物质吸积到活动星系核（AGN）中心的超大质量黑洞上时，X射线就会发射出来。我们提出了一个人口合成模型，占从不断增长的黑洞的总X射线发射;模数转换质量的X射线的效率，这是有效的吸积质量的记录。我们需要这个粒子群合成模型来重现X射线巡天观测到的约束：X射线计数、观测到的康普顿厚度活动星系核的比例[log（NH/cm−2）> 24]，以及考虑选择偏差后的宇宙X射线背景光谱（CXB）。在过去的十年中，XMM-牛顿、钱德拉、努斯塔和斯威夫特-BAT的X射线测量大大改善了观测限制。我们发现，没有现有的X射线光度函数（XLF）一致地再现所有这些观测。我们考虑到活动星系核光谱的不确定性，并使用神经网络来计算一个XLF，适合所有观测到的约束，包括观测到的康普顿厚数计数和分数。这个新的粒子数合成模型表明，在z = 0.1（1.0）范围内的活动星系核中，有50% ± 9%（56% ± 7%）是康普顿厚度的。
As matter accretes onto the central supermassive black holes in active galactic nuclei (AGNs), X-rays are emitted. We present a population synthesis model that accounts for the summed X-ray emission from growing black holes; modulo the efficiency of converting mass to X-rays, this is effectively a record of the accreted mass. We need this population synthesis model to reproduce observed constraints from X-ray surveys: the X-ray number counts, the observed fraction of Compton-thick AGNs [log (NH/cm−2) > 24], and the spectrum of the cosmic X-ray background (CXB), after accounting for selection biases. Over the past decade, X-ray surveys by XMM-Newton, Chandra, NuSTAR, and Swift-BAT have provided greatly improved observational constraints. We find that no existing X-ray luminosity function (XLF) consistently reproduces all these observations. We take the uncertainty in AGN spectra into account and use a neural network to compute an XLF that fits all observed constraints, including observed Compton-thick number counts and fractions. This new population synthesis model suggests that, intrinsically, 50% ± 9% (56% ± 7%) of all AGNs within z ≃ 0.1 (1.0) are Compton-thick.