So far the masses of about 50 active galactic nuclei (AGNs) have been measured through the reverberation mapping technique (RM). Most measurements have been performed for objects of moderate luminosity and redshift, based on Hβ, which is also used to calibrate the scaling relation that allows single-epoch (SE) mass determination based on AGN luminosity and the width of different emission lines. Due to the complex structure and gas dynamics of the relevant emission region, the SE masses obtained from the C IV(1549 ?) line show a large spread around the mean values. Direct RM measures of C IV exist for only six AGNs of low luminosity and redshift, and only one luminous quasar. Since 2003, we have collected photometric and spectroscopic observations of PG1247+267, the most luminous quasar ever analyzed for RM. We provide light curves for the continuum and for C IV(1549 ?) and C III](1909 ?), and measures of the reverberation time lags based on the SPEAR method. The sizes of the line emission regions assume a ratio of R C III]/R C IV ~ 2, similar to the case of Seyfert galaxies, indicating for the first time a similar ionization stratification in a luminous quasar and low-luminosity nuclei. Due to the relatively small size of the broad line region and the relatively narrow line widths, we estimate a small mass and an anomalously high Eddington ratio. We discuss the possibility that either the shape of the emission region or an amplification of the luminosity caused by gravitational lensing may be partly responsible for the result.
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机译：到目前为止，已经通过混响映射技术（RM）测量了约50个活跃银河核（AGN）的质量。已基于Hβ对中等亮度和红移的对象执行了大多数测量，该测量还用于校准比例关系，该比例关系允许基于AGN亮度和不同发射线的宽度确定单历元（SE）质量。由于相关发射区域的复杂结构和气体动力学，从C IV（1549？）线获得的SE质量在平均值附近显示出较大的分布。 C IV的直接RM量度仅存在于六个低发光度和红移的AGN中，并且仅存在一个发光类星体。自2003年以来，我们收集了PG1247 + 267的光度学和光谱学观察结果，这是有史以来对RM进行分析的最发光的类星体。我们提供了连续体和C IV（1549？）和C III]（1909？）的光曲线，并基于SPEAR方法测量了混响时滞。类似于塞弗特星系的情况，线发射区的大小假定为R C III] / R C IV〜2的比率，这首次表明发光类星体和低发光核中的类似电离分层。由于宽线区域的尺寸相对较小，线宽度相对较窄，我们估计质量较小且爱丁顿比率异常高。我们讨论了由引力透镜引起的发射区域形状或发光度放大可能部分负责结果的可能性。
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