New constraints on Lyman-a opacity using 92 quasar lines of sight
New constraints on Lyman-a opacity using 92 quasar lines of sight
复制标题
莱曼的新约束——使用 92 条类星体视线的不透明度
DOI：
10.1017/s174392131700864x
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Bosman S
中科院分区：
文献类型：
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作者：
Bosman S
z > 5.3 时 Lyman-α 不透明度的大分散一直是一个持续的谜团，引发了一系列数值模型的出现。在这些红移处已经排除了均匀的紫外线背景，但尚不清楚任何提出的模型是否会产生足够的不均匀性。在本文中，我们提供了测量的更新，首先强调了这个问题：沿高 z 类星体视线的莱曼-α 有效光学深度。由于 DES-VHS、SHELLQ 和 SDSS 的合作以及新的缩减和光谱，我们在此类研究中的样本量几乎增加了两倍。我们发现，在 5.1 < z < 5.3 以及更高的红移范围内，均匀 UVB 模型被排除，这令人困惑。我们在 z ∼ 6 处提供了第一个此类测量结果。我们面对这些数据的数值模型都无法重现观察到的散射。
The large scatter in Lyman-α opacity at z > 5.3 has been an ongoing mystery, prompting a flurry of numerical models. A uniform ultra-violet background has been ruled out at those redshifts, but it is unclear whether any proposed models produce sufficient inhomogeneities. In this paper we provide an update on the measurement which first highlighted the issue: Lyman-α effective optical depth along high-z quasar lines of sight. We nearly triple on the previous sample size in such a study thanks to the cooperation of the DES-VHS, SHELLQs, and SDSS collaborations as well as new reductions and spectra. We find that a uniform UVB model is ruled out at 5.1 < z < 5.3, as well as higher redshifts, which is perplexing. We provide the first such measurements at z ∼ 6. None of the numerical models we confronted to this data could reproduce the observed scatter.