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New constraints on Lyman-α opacity using 92 quasar lines of sight
Published online by Cambridge University Press: 08 May 2018
Abstract
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.
- Type
- Contributed Papers
- Information
- Proceedings of the International Astronomical Union , Volume 12 , Symposium S333: Peering towards Cosmic Dawn , October 2017 , pp. 234 - 237
- Copyright
- Copyright © International Astronomical Union 2018