论文标题
在吸收选择的高红移星系中对冷中性培养基的统计数据进行建模
Modeling the Statistics of the Cold Neutral Medium in Absorption-selected High-redshift Galaxies
论文作者
论文摘要
我们提出了高降射（Z〜2.5）吸收系统中冷中性气体选择功能的统计模型。该模型基于星际培养基中中性气的规范两相模型，仅包含一个参数，我们没有直接的观察性先验：即在z = 2.5时l* halo的中心压力（p*）。使用强烈的Hi-Selected吸收器中冷气吸收分数的观察，我们能够限制P*。该模型同时再现了HI和H $ _2 $的列密度分布，我们在$ l_ {Cnm} = 12 \ times 10^{ - 3} $处得出了预期的冷气的总发病率。与最近测量CI选择吸收剂的发生率（ew $ _ {CI \，1560} $>0.4Å）相比，我们模型的$ L_ {CNM} $的值表明，总冷气的约15％会导致强大的CI吸收（EW>0.4Å）。然而，CI线是冷气的极为有用的探针，因为它们相对容易检测并在物理条件下提供直接限制。最后，我们的模型自愿重现了冷气体吸收剂的比例，它的函数是N（hi）。
We present a statistical model of the selection function of cold neutral gas in high-redshift (z~2.5) absorption systems. The model is based on the canonical two-phase model of the neutral gas in the interstellar medium and contains only one parameter for which we do not have direct observational priors: namely the central pressure (P*) of an L* halo at z=2.5. Using observations of the fraction of cold gas absorption in strong HI-selected absorbers, we are able to constrain P*. The model simultaneously reproduces the column density distributions of HI and H$_2$, and we derive an expected total incidence of cold gas at z~2.5 of $l_{CNM} = 12\times 10^{-3}$. Compared to recent measurements of the incidence of CI-selected absorbers (EW$_{CI\,1560}$ > 0.4 Å), the value of $l_{CNM}$ from our model indicates that only ~15% of the total cold gas would lead to strong CI absorption (EW > 0.4 Å). Nevertheless, CI lines are extremely useful probes of the cold gas as they are relatively easy to detect and provide direct constraints on the physical conditions. Lastly, our model self-consistently reproduces the fraction of cold gas absorbers as a function of N(HI).
