The VLT LBG redshift survey – VI. Mapping H i in the proximity of z ∼ 3 LBGs with X-Shooter

Bielby, R.M.; Shanks, T.; Crighton, N.H.M.; Bornancini, C.G.; Infante, L.; Lambas, D.G.; Minniti, D.; Morris, S.L.; Tummuangpak, P.

Abstract

We present an analysis of the spatial distribution and dynamics of neutral hydrogen gas around galaxies using new X-Shooter observations of z ∼ 2.5–4 quasars. Adding the X-Shooter data to our existing data set of high-resolution quasar spectroscopy, we use a total sample of 29 quasars alongside ∼1700 Lyman Break Galaxies (LBGs) in the redshift range 2 ≲ z ≲ 3.5. We measure the Lyα forest auto-correlation function, finding a clustering length of s0 = 0.081 ± 0.006 h−1 Mpc, and the cross-correlation function with LBGs, finding a cross-clustering length of s0 = 0.27 ± 0.14 h−1 Mpc and power-law slope γ = 1.1 ± 0.2. Our results highlight the weakly clustered nature of neutral hydrogren systems in the Lyα forest. Building on this, we make a first analysis of the dependence of the clustering on absorber strength, finding a clear preference for stronger Lyα forest absorption features to be more strongly clustered around the galaxy population, suggesting that they trace on average higher mass haloes. Using the projected and 2-D cross-correlation functions, we constrain the dynamics of Lyα forest clouds around z ∼ 3 galaxies. We find a significant detection of large-scale infall of neutral hydrogen, with a constraint on the Lyα forest infall parameter of βF = 1.02 ± 0.22.

Citation

Bielby, R., Shanks, T., Crighton, N., Bornancini, C., Infante, L., Lambas, D., …Tummuangpak, P. (2017). The VLT LBG redshift survey – VI. Mapping H i in the proximity of z ∼ 3 LBGs with X-Shooter. Monthly Notices of the Royal Astronomical Society, 471(2), 2174-2186. https://doi.org/10.1093/mnras/stx1772

• Journal Article Type: Article
• Acceptance Date: Jul 12, 2017
• Online Publication Date: Jul 14, 2017
• Publication Date: Jul 14, 2017
• Deposit Date: Aug 31, 2017
• Publicly Available Date: Sep 5, 2017
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 471
• Issue: 2
• Pages: 2174-2186
• DOI: https://doi.org/10.1093/mnras/stx1772
• Public URL: https://durham-repository.worktribe.com/output/1350482