The Sherwood simulation suite: overview and data comparisons with the Lyman-α forest at redshifts 2≤z≤5

Bolton, James S. and Puchwein, Ewald and Sijacki, Debora and Haehnelt, Martin G. and Kim, Tae-Sun and Meiksin, Avery and Regan, John A. and Viel, Matteo (2017) The Sherwood simulation suite: overview and data comparisons with the Lyman-α forest at redshifts 2≤z≤5. Monthly Notices of the Royal Astronomical Society, 464 (1). pp. 897-914. ISSN 1365-2966

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Abstract

We introduce a new set of large-scale, high-resolution hydrodynamical simulations of the intergalactic medium: the Sherwood simulation suite. These are performed in volumes of 103–1603h−3 comoving Mpc3, span almost four orders of magnitude in mass resolution with up to 17.2 billion particles, and employ a variety of physics variations including warm dark matter and galactic outflows. We undertake a detailed comparison of the simulations to high-resolution, high signal-to-noise observations of the Ly α forest over the redshift range 2 ≤ z ≤ 5. The simulations are in very good agreement with the observational data, lending further support to the paradigm that the Ly α forest is a natural consequence of the web-like distribution of matter arising in Λcold dark matter cosmological models. Only a small number of minor discrepancies remain with respect to the observational data. Saturated Ly α absorption lines with column densities NHI>1014.5cm−2 at 2 < z < 2.5 are underpredicted in the models. An uncertain correction for continuum placement bias is required to match the distribution and power spectrum of the transmitted flux, particularly at z > 4. Finally, the temperature of intergalactic gas in the simulations may be slightly too low at z = 2.7 and a flatter temperature–density relation is required at z = 2.4, consistent with the expected effects of non-equilibrium ionization during He ii reionization.

Item Type: Article
Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2016 Royal Astronomical Society Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Keywords: methods: numerical, intergalactic medium, quasars: absorption lines
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: https://doi.org/10.1093/mnras/stw2397
Depositing User: Bolton, James
Date Deposited: 22 Sep 2016 13:00
Last Modified: 17 Dec 2016 06:23
URI: http://eprints.nottingham.ac.uk/id/eprint/37042

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