暗能量光谱仪（DESI）中高红移类星体的堆叠回声映射。I. 可行性分析
Stacked Reverberation Mapping of High Redshift Quasars in DESI. I. Feasibility Analysis
AI总结：
研究利用DESI对高红移类星体进行堆叠回声映射的可行性，通过创建模拟光变曲线，用JAVELIN代码结合稀疏光谱与光度数据测试，成功恢复C IV滞后，研究观测因素影响，为相关项目开辟道路，提供经济替代方案。
AI中文摘要：
类星体的宽线区域长期以来一直通过回声映射技术进行探测，该技术测量连续谱和宽发射线变化之间的时间延迟。堆叠回声映射已被提议作为一种观测成本较低的传统方法替代方案。这种整体方法还减少了小样本统计的偏差。暗能量光谱仪（DESI）正在进行迄今为止最广泛的类星体光谱调查。我们创建模拟光变曲线，模拟在红移$1.48<z<5.2$和光度$44.68 \leq \log L_{1350} \lambda / \mathrm{erg\,s^{-1}} \leq 45.99$下预期的DESI类星体观测，以使用稀疏光谱数据与采样良好的光度数据配对来测试堆叠回声映射的可行性。该管道使用滞后估计代码JAVELIN，使用仅由几个具有不规则节奏的光谱历元（2 - 10）组成的光谱光变曲线，成功在真实值的一个标准差内恢复了模拟的C IV滞后。我们研究了包括C IV通量误差大小、堆叠类星体数量和光谱历元计数在内的观测因素如何影响性能。这项工作为未来对具有≥2次光谱观测的类星体进行大规模光谱调查的堆叠回声映射项目开辟了一条道路。我们的结果表明了一种经济的替代方案，用于将半径 - 光度关系约束和扩展到更高的红移和光度。随后，这种关系可以在这些遥远区域的单历元黑洞质量测量和类星体宇宙学中更可靠地使用。
英文摘要：
The broad line region of quasars has long been probed by reverberation mapping techniques that measure time lags between continuum and broad emission line variations. Stacked reverberation mapping has been proposed as a less observationally expensive alternative to traditional methods. This ensemble approach also reduces biases from small-number statistics. The Dark Energy Spectroscopic Instrument (DESI) is conducting the most extensive spectroscopic survey of quasars to date. We create mock light curves emulating expected DESI quasar observations at redshifts $1.48<z<5.2$ and luminosities $ 44.68 \leq \log L_{1350} λ/ \mathrm{erg\,s^{-1}} \leq 45.99 $ to test stacked reverberation mapping feasibility using sparse spectroscopic data paired with well-sampled photometric data. The pipeline, using the lag estimation code JAVELIN, successfully recovers the simulated C IV lags within one sigma of the true values using spectroscopic light curves composed of only a few spectral epochs (2-10) with irregular cadences. We investigate how observational factors, including C IV flux error magnitude, number of stacked quasars, and spectral epoch count, affect performance. This work motivates a pathway for future stacked reverberation mapping projects with large scale spectroscopic surveys of quasars having $\geq 2$ spectroscopic observations. Our results suggest an economical alternative for constraining and extending the radius-luminosity relation to higher redshifts and luminosities. Subsequently, this relation can be employed more reliably in single-epoch black hole mass measurements and quasar cosmology in these distant regimes.
