论文标题
主动银河核中的稀有宽线区域：混响映射中的异常响应以及对弱发射线类星体的影响
Rarefied Broad-Line Regions in Active Galactic Nuclei: Anomalous Responses in Reverberation Mapping and Implications for Weak Emission-Line Quasars
论文作者
论文摘要
混响映射（RM）是一种广泛使用的方法，用于探测活性银河核（AGNS）中宽线区域（BLR）的物理。有越来越多的初步证据表明，广泛排放线的RM行为受BLR密度的影响，但是，从理论角度来看，影响的影响并未被系统地研究。在本文中，我们采用本地发射云模型，并使用Cloudy来获得不同BLR密度的突出紫外线和光学发射线的一维转移函数。我们发现，BLR密度对RM行为的影响主要三个方面。首先，在RM观测值中，稀有BLR（气体密度低）可能会显示出异常的响应。它们的发射线光曲线呈现连续光曲线的变化，这可能在某些UV RM运动中观察到。其次，AGN中不同的BLR密度可能导致时间滞后与排放线的等效宽度之间的相关性，并且可能有助于半径 - 亮度关系的散射。第三，BLR密度的变化可能解释了不同年份各个对象中时间滞后的变化。一些弱排放线类星体（WLQ）可能是稀有BLR的极端情况。我们预测他们的RM观察结果可能显示出异常的反应。
Reverberation mapping (RM) is a widely-used method for probing the physics of broad-line regions (BLRs) in active galactic nuclei (AGNs). There are increasing preliminary evidences that the RM behaviors of broad emission lines are influenced by BLR densities, however, the influences have not been investigated systematically from theoretical perspective. In the present paper, we adopt locally optimally emitting cloud model and use CLOUDY to obtain the one-dimensional transfer functions of the prominent UV and optical emission lines for different BLR densities. We find that the influences of BLR densities to RM behaviors have mainly three aspects. First, rarefied BLRs (with low gas densities) may show anomalous responses in RM observations. Their emission-line light curves inversely response the variations of continuum light curves, which may have been observed in some UV RM campaigns. Second, the different BLR densities in AGNs may result in correlations between the time lags and equivalent widths of emission lines, and may contribute to the scatters of the radius-luminosity relationships. Third, the variations of BLR densities may explain the changes of time lags in individual objects in different years. Some weak emission-line quasars (WLQs) are probably extreme cases of rarefied BLRs. We predict that their RM observations may show the anomalous responses.
