Reionization and thermal evolution of a photoionized intergalactic medium.
Reionization and thermal evolution of a photoionized intergalactic medium.
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DOI：
10.1093/mnras/266.2.343
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发表时间：
1994-01
影响因子：
4.8
通讯作者：
J. Miralda-Escudé;M. Rees
中科院分区：
文献类型：
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作者：
J. Miralda-Escudé;M. Rees
在大多数星系际介质再电离的模型中，紫外线辐射源在其周围产生电离区域，这些电离区域不断扩大，直到它们重叠。当气体进入其中一个电离区域时，它会受到脉冲加热。我们讨论了各种物理效应，确定电离前沿通过后的气体的温度。具有不同光谱的源可能会将周围的气体加热到不同的温度，从而造成宇宙中气体温度的大规模不均匀性。氦的存在是特别重要的，因为它允许后再电离温度达到高达105 × 104K的值。气体坍缩成晕时，随后的绝热加热可以使温度进一步升高，这解释了微晕模型中Lyα云的大b参数
In most models of the reionization of the intergalactic medium, sources of UV radiation create ionized regions around them which expand until they overlap. The gas is impulsively heated when it enters one of these ionized regions. We discuss the various physical effects that determine the temperature of the gas after the passage of the ionization front. Sources with different spectra may heat the surrounding gas to different temperatures, creating large-scale inhomogeneities of the gas temperature in the Universe. The presence of helium is particularly important, since it allows the post-reionization temperature to reach values as high as ∼ 5×10 4 K. Subsequent adiabatic heating as gas collapses into haloes can raise the temperature even more, explaining large b-parameters in Lyα clouds in the minihalo model