AI 中文总结
本研究开发了新的滞后测量包LITMUS，利用贝叶斯证据识别假阳性滞后，分析OzDES样本发现以往RM研究高估了滞后置信度，不同发射线的AGN反响百分比存在显著差异。
AI 中文摘要
活动星系核（AGN）的反响映射（RM）通过测量连续谱与发射线变异性之间的时间延迟，为宽线区的几何结构和运动学提供了最直接的探测手段之一。现代RM巡天常因信噪比低和混叠效应而难以开展滞后测量，其中数据的季节间隙会导致多峰滞后后验分布，这对常用拟合工具（如JAVELIN）的可靠性构成挑战，这类工具会返回较高的假阳性率。我们实现了新的滞后测量包LITMUS，并引入了利用贝叶斯证据识别假阳性滞后测量的新框架，同时探究在OzDES和SDSS等高红移工业级巡天中，有多少AGN存在可探测的滞后。我们的分析与以往RM研究在六个关键方面存在差异：（i）我们的推断对此前未被充分诊断的混叠数值分量具有鲁棒性；（ii）我们对所有源采用一致的方法；（iii）充分边缘化了AGN本征变异性的不确定性；（iv）通过贝叶斯模型比较而非启发式指标评估滞后显著性；（v）通过与随机偶然恢复结果的对比量化假阳性率；（vi）使用边际似然区分数据中无法探测到滞后的源与无反响证据的源。将该方法应用于OzDES样本，我们发现以往RM研究可能高估了已恢复滞后的置信度，且MgII线的反响百分比较低（依假设为3%-28%），而CIV线、尤其是Hβ线的百分比高得多，Hβ线的结果与100%一致。我们还呈现了OzDES样本中一组重新分析的滞后，其可靠性得到了更准确的量化。
英文摘要
Reverberation mapping of active galactic nuclei provides one of the most direct probes of the geometry and kinematics of the broad-line region by measuring time delays between continuum and line variability. Modern RM surveys frequently suffer difficulties with lag measurements due to poor signal to noise and aliasing, whereby multimodal lag posterior distributions arise due to seasonal gaps in our data. These challenge the reliability of commonly used fitting tools such as JAVELIN, which can return a high rate of false positives. We implement a new lag measurement package, LITMUS, and introduce a new framework that uses Bayesian evidence to identify false positive lag measurements, as well as examine the question of how many AGN present detectable lags in high redshift industrial scale surveys like OzDES and SDSS. Our analysis differs from previous RM studies in six key respects: (i) our inference is robust to the previously under-diagnosed numerical component of aliasing, (ii) we use a consistent methodology for all sources, (iii) uncertainty in the underlying AGN variability is fully marginalised, (iv) lag significance is assessed via Bayesian model comparison rather than heuristic metrics, (v) false-positive rates are quantified by comparison against random-chance recoveries and (vi) we use marginal likelihoods to distinguish between sources where a lag is not detectable in our data and sources that show no evidence of reverberation. Applied to the OzDES sample, we find that previous RM studies are likely to have overestimated the confidence of recovered lags, and we find a stark contrast between a low reverberation percentage for the MgII line (3-28% depending on assumptions) and much higher percentages in the CIV and especially the H$β$ line, which is consistent with 100%. We also present a re-analysed set of lags from the OzDES sample with better quantified reliabilities
Comments32 Pages, 21 Figures
