标题： 活动星系核和类星体中吸积大质量黑洞的平均辐射效率 显示英文标题

标题： On the Mean Radiative Efficiency of Accreting Massive Black Holes in AGNs And QSOs

摘要： 辐射效率是一个重要的物理参数，用于描述吸积到大质量黑洞（MBHs）的吸积物质中转化为辐射能量的比例。 通过最简单的So{\l }tan论证，可以通过将本地宇宙中MBH的质量密度与活动星系核（AGN）/类星体（QSO）阶段MBH吸积的质量密度相匹配来估计MBH的辐射效率。 在本文中，我们通过结合各种MBH质量与其宿主星系特性之间的关系的确定方法，以及这些星系特性的分布函数来估计本地MBH质量密度。 我们还通过使用文献中各种AGN/QSO X射线光度函数来估计AGN和QSO辐射的总能量密度。 然后，我们获得了几百个AGN/QSO平均辐射效率的估计值。 在假设这些估计彼此独立且没有系统效应的前提下，我们应用Gott等人的中位数统计方法\cite{got01}，并发现AGN/QSO的平均辐射效率为$\epsilon=0.105^{+0.006}_{-0.008}$，这与经典值$\sim0.1$一致。 考虑到目前可用的X射线调查可能遗漏了大约$20\%$个Compton厚天体，真实的平均辐射效率可能实际上是$\sim 0.12$。 显示英文摘要

摘要： Radiative efficiency is an important physical parameter that describes the fraction of accretion material converted to radiative energy for accretion onto massive black holes (MBHs). With the simplest So{\l}tan argument, the radiative efficiency of MBHs can be estimated by matching the mass density of MBHs in the local universe to the accreted mass density by MBHs during AGN/QSO phases. In this paper, we estimate the local MBH mass density through a combination of various determinations of the correlations between the masses of MBHs and the properties of MBH host galaxies, with the distribution functions of those galaxy properties. We also estimate the total energy density radiated by AGNs and QSOs by using various AGN/QSO X-ray luminosity functions in the literature. We then obtain several hundred estimates of the mean radiative efficiency of AGNs/QSOs. Under the assumption that those estimates are independent of each other and free of systematic effects, we apply the median statistics as described by Gott et al.\cite{got01} and find the mean radiative efficiency of AGNs/QSOs is $\epsilon=0.105^{+0.006}_{-0.008}$, which is consistent with the canonical value $\sim0.1$. Considering that about $20\%$ Compton-thick objects may be missed from current available X-ray surveys, the true mean radiative efficiency may be actually $\sim 0.12$.