Ultraviolet Line Emission from Metals in the Low-Redshift Intergalactic Medium
Ultraviolet Line Emission from Metals in the Low-Redshift Intergalactic Medium
复制标题
低红移星际介质中金属的紫外线发射
DOI：
10.1086/382727
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
L. Hernquist
中科院分区：
文献类型：
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作者：
S. Furlanetto;J. Schaye;V. Springel;L. Hernquist
我们使用一个高分辨率的宇宙学模拟，包括流体动力学，多相星星形成，和星系风预测的金属线发射在z ~ 0从星系际介质（IGM）的分布。我们主要研究了两个紫外双态跃迁OVI λλ1032，1038和CIV λλ1548，1551。中等过密度的暗条的发射比背景小几个数量级，但在背景以上可以检测到T ~ 105-105.5 K和特征尺寸~50-100 kpc的富集致密区域的孤立发射。我们表明，从这些地区的排放量是大大大于当我们假设一个统一的IGM金属丰度时，我们使用的模拟（其中包括通过银河风富集）预测的金属丰度。发光区域对应于最近受到银河风影响的体积。我们还表明，线发射聚集在尺度~1小时-1兆秒差距。我们认为，尽管这些转变并不是温热星系际介质的有效示踪剂，但它们确实提供了研究星系际介质化学富集和星系风物理的途径。
We use a high-resolution cosmological simulation that includes hydrodynamics, multiphase star formation, and galactic winds to predict the distribution of metal line emission at z ~ 0 from the intergalactic medium (IGM). We focus on two ultraviolet doublet transitions, O VI λλ1032, 1038 and C IV λλ1548, 1551. Emission from filaments with moderate overdensities is orders of magnitude smaller than the background, but isolated emission from enriched dense regions with T ~ 105-105.5 K and characteristic size ~50-100 kpc can be detected above the background. We show that the emission from these regions is substantially greater when we use the metallicities predicted by the simulation (which includes enrichment through galactic winds) than when we assume a uniform IGM metallicity. Luminous regions correspond to volumes that have recently been influenced by galactic winds. We also show that the line emission is clustered on scales ~1 h-1 Mpc. We argue that although these transitions are not effective tracers of the warm-hot intergalactic medium, they do provide a route to study the chemical enrichment of the IGM and the physics of galactic winds.