论文标题
使用\ civ \ baldwin效果的宇宙距离度量
A measure of cosmological distance using the \civ\ Baldwin effect in quasars
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
We use the anticorrelation between the equivalent width (EW) of the C\,\textsc{iv} 1549 Å emission line and the continuum luminosity in the quasars rest frame (Baldwin effect) to measure their luminosity distance as well as estimate cosmological parameters. We obtain a sample of 471 Type I quasars with the UV/optical spectra and EW (C\,\textsc{iv}) measurements in the redshift range of $2.3< z< 7.1$ including 25 objects at $5 < z < 7.1$, which can be used to investigate the C\,\textsc{iv} Baldwin effect and determine cosmological luminosity distance. The relation $EW(C\,\textsc{iv}) \propto {(λ{L_λ})^γ}$ can be applied to check the inverse correlation between the C\,\textsc{iv} EW and ${L_λ}$ of quasars and give their distance, and the data suggest that the EW of C\,\textsc{iv} is inversely correlated with continuum monochromatic luminosities. On the other hand, we also consider dividing the Type I quasars sample into various redshift bins, which can be used to check if the C\,\textsc{iv} EW-luminosity relation depends on the redshift. Finally, we apply a combination of Type I quasars and SNIa Pantheon to test the property of dark energy concerning whether or not its density deviates from the constant, and give the statistical results.
