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

Bolton, James S.; Puchwein, Ewald; Sijacki, Debora; Haehnelt, Martin G.; Kim, Tae-Sun; Meiksin, Avery; Regan, John A.; Viel, Matteo

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.

Citation

Bolton, J. S., Puchwein, E., Sijacki, D., Haehnelt, M. G., Kim, T., Meiksin, A., …Viel, M. (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), 897-914. https://doi.org/10.1093/mnras/stw2397

• Journal Article Type: Article
• Acceptance Date: Sep 19, 2016
• Online Publication Date: Sep 21, 2016
• Publication Date: Jan 1, 2017
• Deposit Date: Sep 22, 2016
• Publicly Available Date: Sep 22, 2016
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 464
• Issue: 1
• Pages: 897-914
• DOI: https://doi.org/10.1093/mnras/stw2397
• Keywords: methods: numerical, intergalactic medium, quasars: absorption lines
• Public URL: https://nottingham-repository.worktribe.com/output/830542
• Publisher URL: http://mnras.oxfordjournals.org/content/464/1/897
• 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.