García, L. A.Tescari, E.Ryan-Weber, E. V.Wyithe, J. S.B.2026-01-022026-01-020035-8711ORCID:/0000-0001-7956-9758/work/195266041https://hdl.handle.net/1885/733802378We present a theoretical study of intergalactic metal absorption lines imprinted in the spectra of distant quasars during and after the Epoch of Reionization (EoR). We use high-resolution hydrodynamical simulations at high redshift (4 < z < 8), assuming a uniform UV background Haardt-Madau 12, post-processing with CLOUDY photoionization models and Voigt profile fitting to accurately calculate column densities of the ions C II, CIV, Si II, Si IV and OI in the intergalactic medium (IGM). In addition, we generate mock observations of neutral hydrogen (H I) at z < 6. Our simulations successfully reproduce the evolution of the cosmological mass density (Ω) of CII and C IV, with ΩC II exceeding ΩC IV at z > 6, consistent with the current picture of the tail of the EoR. The simulated C II exhibits a bimodal distribution with large absorptions in and around galaxies, and some traces in the lower density IGM. We find some discrepancies between the observed and simulated column density relationships among different ionic species at z = 6, probably due to uncertainties in the assumed UV background. Finally, our simulations are in good agreement with observations of the HI column density distribution function at z = 4 and the HI cosmological mass density ΩHI at 4 < z < 6.Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. The numerical simulations were run using the Raijin distributed-memory cluster from the NCI facility, post-processed with the Edward HPC machine from the University of Melbourne and analysed with the gSTAR supercomputer at Swinburne University of Technology. This work was supported by the Flagship Allocation Scheme of the NCI National Facility at the ANU. The authors acknowledge CAASTRO for funding and allocating time for the project Diagnosing hydro hydrogen reionization with metal absorption line ratios (fy6) during 2015 and 2016. LAG thanks Valentina D'Odorico and Neil Crighton for providing their observational data in private communications and Jeff Cooke for the insightful discussions. ERWacknowledges ARC DP 1095600. We also thank the anonymous referee for providing valuable comments that considerably improved our manuscript and Klaus Dolag for his help with the technical details of the SPH code.16enPublisher Copyright: © 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.Cosmology: theoryIntergalactic mediumMethods: numerical2017-09-1110.1093/mnras/stx137185023738875