宇宙学模拟中的厚吸收和薄吸收- HI
Through Thick and Thin - HI Absorption in Cosmological Simulations
摘要：
我们调查的列密度分布函数的中性氢在红移z = 3使用宇宙学模拟的星系形成的超大规模模拟（OWLS）项目。基础模拟包括重力、流体动力学、恒星形成、超新星反馈、恒星风、化学动力学以及在均匀紫外背景下的逐元素冷却。在后处理过程中，不引入任何自由参数，采用精确的反向光线追迹算法和气体压强与分子质量分数之间的经验关系，对自屏蔽和分子氢的形成进行了处理。模拟再现了观测到的z = 3丰富的Ly-A森林，莱曼极限和阻尼Ly-A HI吸收系统探测类星体视线超过10个数量级的柱密度。自屏蔽使NHI > 10^18 cm-2时的柱密度分布变陡，而转化为完全中性气体和HI转化为H2分别使NHI = 10^20.3 cm-2和NHI = 10^21.5 cm-2时的柱密度分布变陡。
英文摘要：
We investigate the column density distribution function of neutral hydrogen at redshift z = 3 using a cosmological simulation of galaxy formation from the OverWhelmingly Large Simulations (OWLS) project. The base simulation includes gravity, hydrodynamics, star formation, supernovae feedback, stellar winds, chemodynamics, and element-by-element cooling in the presence of a uniform UV background. Self-shielding and formation of molecular hydrogen are treated in post-processing, without introducing any free parameters, using an accurate reverse ray-tracing algorithm and an empirical relation between gas pressure and molecular mass fraction. The simulation reproduces the observed z = 3 abundance of Ly-A forest, Lyman Limit and Damped Ly-A HI absorption systems probed by quasar sight lines over ten orders of magnitude in column density. Self-shielding flattens the column density distribution for NHI > 10^18 cm-2, while the conversion to fully neutral gas and conversion of HI to H2 steepen it around column densities of NHI = 10^20.3 cm-2 and NHI = 10^21.5 cm-2, respectively.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
