The impact of temperature fluctuations on the large-scale clustering of the Lyα forest

We develop a semi-analytic method for assessing the impact of the large-scale IGM temperature fluctuations expected following He ii reionization on three-dimensional clustering measurements of the Lyα forest. Our methodology builds upon the existing large volume, mock Lyα forest survey simulations p...

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Main Authors: Greig, Bradley, Bolton, James S., Wyithe, J. Stuart B.
Format: Article
Published: Oxford University Press 2015
Subjects:
Online Access:https://eprints.nottingham.ac.uk/42510/
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author Greig, Bradley
Bolton, James S.
Wyithe, J. Stuart B.
author_facet Greig, Bradley
Bolton, James S.
Wyithe, J. Stuart B.
author_sort Greig, Bradley
building Nottingham Research Data Repository
collection Online Access
description We develop a semi-analytic method for assessing the impact of the large-scale IGM temperature fluctuations expected following He ii reionization on three-dimensional clustering measurements of the Lyα forest. Our methodology builds upon the existing large volume, mock Lyα forest survey simulations presented by Greig et al. by including a prescription for a spatially inhomogeneous ionizing background, temperature fluctuations induced by patchy He ii photoheating and the clustering of quasars. This approach enables us to achieve a dynamic range within our semi-analytic model substantially larger than currently feasible with computationally expensive, fully numerical simulations. The results agree well with existing numerical simulations, with large-scale temperature fluctuations introducing a scale-dependent increase in the spherically averaged 3D Lyα forest power spectrum of up to 20–30 per cent at wavenumbers k ∼ 0.02 Mpc− 1. Although these large-scale thermal fluctuations will not substantially impact upon the recovery of the baryon acoustic oscillation scale from existing and forthcoming dark energy spectroscopic surveys, any complete forward modelling of the broad-band term in the Lyα correlation function will none the less require their inclusion.
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spelling nottingham-425102020-05-04T17:01:13Z https://eprints.nottingham.ac.uk/42510/ The impact of temperature fluctuations on the large-scale clustering of the Lyα forest Greig, Bradley Bolton, James S. Wyithe, J. Stuart B. We develop a semi-analytic method for assessing the impact of the large-scale IGM temperature fluctuations expected following He ii reionization on three-dimensional clustering measurements of the Lyα forest. Our methodology builds upon the existing large volume, mock Lyα forest survey simulations presented by Greig et al. by including a prescription for a spatially inhomogeneous ionizing background, temperature fluctuations induced by patchy He ii photoheating and the clustering of quasars. This approach enables us to achieve a dynamic range within our semi-analytic model substantially larger than currently feasible with computationally expensive, fully numerical simulations. The results agree well with existing numerical simulations, with large-scale temperature fluctuations introducing a scale-dependent increase in the spherically averaged 3D Lyα forest power spectrum of up to 20–30 per cent at wavenumbers k ∼ 0.02 Mpc− 1. Although these large-scale thermal fluctuations will not substantially impact upon the recovery of the baryon acoustic oscillation scale from existing and forthcoming dark energy spectroscopic surveys, any complete forward modelling of the broad-band term in the Lyα correlation function will none the less require their inclusion. Oxford University Press 2015-01-09 Article PeerReviewed Greig, Bradley, Bolton, James S. and Wyithe, J. Stuart B. (2015) The impact of temperature fluctuations on the large-scale clustering of the Lyα forest. Monthly Notices of the Royal Astronomical Society, 447 (3). pp. 2503-2511. ISSN 1365-2966 intergalactic medium quasars: absorption lines cosmology: theory large-scale structure of Universe https://academic.oup.com/mnras/article/447/3/2503/2892859/The-impact-of-temperature-fluctuations-on-the doi:10.1093/mnras/stu2624 doi:10.1093/mnras/stu2624
spellingShingle intergalactic medium
quasars: absorption lines
cosmology: theory
large-scale structure of Universe
Greig, Bradley
Bolton, James S.
Wyithe, J. Stuart B.
The impact of temperature fluctuations on the large-scale clustering of the Lyα forest
title The impact of temperature fluctuations on the large-scale clustering of the Lyα forest
title_full The impact of temperature fluctuations on the large-scale clustering of the Lyα forest
title_fullStr The impact of temperature fluctuations on the large-scale clustering of the Lyα forest
title_full_unstemmed The impact of temperature fluctuations on the large-scale clustering of the Lyα forest
title_short The impact of temperature fluctuations on the large-scale clustering of the Lyα forest
title_sort impact of temperature fluctuations on the large-scale clustering of the lyα forest
topic intergalactic medium
quasars: absorption lines
cosmology: theory
large-scale structure of Universe
url https://eprints.nottingham.ac.uk/42510/
https://eprints.nottingham.ac.uk/42510/
https://eprints.nottingham.ac.uk/42510/