A metal-poor damped Ly-alpha system at redshift 6.4
Abstract
We identify a strong Ly-alpha damping wing profile in the spectrum of the quasar P183+05 at z=6.4386. Given the detection of several narrow metal absorption lines at z=6.40392, the most likely explanation for the absorption profile is that it is due to a damped Ly-alpha system. However, in order to match the data a contribution of an intergalactic medium 5-38% neutral or additional weaker absorbers near the quasar is also required. The absorption system presented here is the most distant damped Ly-alpha system currently known. We estimate an HI column density (cm), metallicity ([O/H]), and relative chemical abundances of a system consistent with a low-mass galaxy during the first Gyr of the universe. This object is among the most metal-poor damped Ly-alpha systems known and, even though it is observed only ~850 Myr after the big bang, its relative abundances do not show signatures of chemical enrichment by Population III stars.
Keywords
Cite
@article{arxiv.1903.06186,
title = {A metal-poor damped Ly-alpha system at redshift 6.4},
author = {Eduardo Banados and Michael Rauch and Roberto Decarli and Emanuele P. Farina and Chiara Mazzucchelli and Bram P. Venemans and Fabian Walter and Robert A. Simcoe and J. Xavier Prochaska and Thomas Cooper and Frederick B. Davies and Shi-Fan S. Chen},
journal= {arXiv preprint arXiv:1903.06186},
year = {2020}
}
Comments
Updated to match published version