INTERGALACTIC TRANSMISSION AND ITS IMPACT ON THE Lyα LINE
INTERGALACTIC TRANSMISSION AND ITS IMPACT ON THE Lyα LINE
复制标题
星际传输及其对 Lyα 线的影响
DOI：
10.1088/0004-637x/728/1/52
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Razoumov
中科院分区：
文献类型：
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作者：
P. Laursen;J. Sommer;A. Razoumov
我们研究了Lyα波长附近的辐射的星系际传输。在详细的宇宙学水动力模拟中，通过模拟星系际介质（IGM）的视线，研究了在红移2.5 ~ 6.5范围内，IGM对Lyα发射星系的线轮廓形状的影响。特别是，我们表明，考虑到与星系的IGM的密度和速度场的相关性，光谱的蓝色部分可能会明显减少，即使在相对较低的红移。在某些情况下，这可能为经常引用的外流情景提供了一种替代方案，尽管可以得出结论，该模型仍然是观察到的许多不对称Lyα分布的合理解释。应用计算的波长依赖的传输模拟光谱从Lyα发射星系，我们得到的分数的光子在IGM中丢失，除了什么是在星系内部吸收由于尘埃。此外，通过比较计算的Lyα线向蓝方向的辐射透射率与相应的观测值，我们能够将宇宙再电离的时间限制在z = 8.5。
We study the intergalactic transmission of radiation in the vicinity of the Lyα wavelength. Simulating sightlines through the intergalactic medium (IGM) in detailed cosmological hydrosimulations, the impact of the IGM on the shape of the line profile from Lyα emitting galaxies at redshifts from 2.5 to 6.5 is investigated. In particular, we show that taking into account the correlation of the density and velocity fields of the IGM with the galaxies, the blue part of the spectrum may be appreciably reduced, even at relatively low redshifts. This may in some cases provide an alternative to the often-invoked outflow scenario, although it is concluded that this model is still a plausible explanation of the many asymmetric Lyα profiles observed. Applying the calculated wavelength-dependent transmission to simulated spectra from Lyα emitting galaxies, we derive the fraction of photons that are lost in the IGM, in addition to what is absorbed internally in the galaxies due to dust. Moreover, by comparing the calculated transmission of radiation blueward of the Lyα line with corresponding observations, we are able to constrain the epoch when the universe was reionized to z ≲ 8.5.