标题： 喷流星系中的喷流效率与黑洞自旋 显示英文标题

标题： Jet efficiencies and black hole spins in jetted quasars

摘要： 超大质量黑洞（SMBH）以接近爱丁顿吸积率吸积时产生相对论性喷流的机制尚不明确。 简单的理论预期表明，类星体中的SMBH通过薄盘吸积，这种薄盘最多只能产生非常弱的喷流。 这与平坦光谱射电类星体（FSRQs）中强喷流的观测结果相矛盾。 我们使用由\emph{费米}大面积望远镜观测到的伽马射线亮度作为喷流功率的代理，对154个FSRQs样本进行了研究。 假设典型的类星体吸积率，并利用多种方法测量的黑洞质量，我们发现FSRQs的平均喷流产生效率约为10%，且最高可达222%。 我们发现，这一结果与FSRQs围绕快速旋转黑洞（BH）周围的适度薄磁俘获吸积盘一致。 通过使用薄盘喷流的一般相对论磁流体力学（GRMHD）模拟来分析我们的观测数据，我们发现FSRQs的SMBH自旋下限平均为$a_* = 0.59$，且随着黑洞质量的增加，自旋有减小的趋势。 我们的结果与SMBH的合并驱动演化一致。 由于高效率，样本中3%的案例无法用目前Kerr黑洞喷流产生的GRMHD模型解释。 在此过程中，我们发现黑洞质量和$L_\gamma$之间存在相关性，这可能是耀变体伽马射线研究中有用的质量估计器。 显示英文摘要

摘要： The mechanisms responsible for the production of relativistic jets from supermassive black holes (SMBHs) accreting at near-Eddington rates are not well-understood. Simple theoretical expectations indicate that SMBHs in quasars accrete via thin discs which should produce at most very weak jets. This is contradicted by observations of powerful jets in flat-spectrum radio quasars (FSRQs). We use gamma-ray luminosities observed with the \emph{fermi} Large Area Telescope as a proxy of the jet power for a population of 154 FSRQs. Assuming typical quasar accretion rates and using black hole mass measurements from a variety of methods, we find a mean jet production efficiency of about 10 per cent for FSRQs, with values as high as 222 per cent. We find that this is consistent with FSRQs hosting moderately thin, magnetically arrested accretion discs around rapidly spinning black holes (BHs). Modeling our observations using general relativistic magnetohydrodynamic (GRMHD) simulations of jets from thin discs, we find an average lower limit of $a_* = 0.59$ for the SMBH spins of FSRQs, with tendency for the spins to decrease as the black hole mass increases. Our results are consistent with the merger-driven evolution of SMBHs. 3 per cent of the sample cannot be explained by current GRMHD models of jet production from Kerr BHs due to the high efficiencies. Along the way, we find a correlation between BH masses and $L_\gamma$ which may be an useful mass estimator in blazar gamma-ray studies.