2006/01/31 by Emma V. Ryan-Weber, Emma Ryan‐Weber · 10 citations
Environmental Science · Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Impact of Light on Environment and Health #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10010.x
published as Mon.Not.Roy.Astron.Soc. 367 (2006) 1251-1260 · 10 pages, 10 figures, accepted for publication in MNRAS, minor typos fixed and references updated
arxiv created 2006/01/31 · openalex publication_date 2006/03/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The H i Parkes all-sky survey (HIPASS) galaxy catalogue is cross-correlated with known low redshift, low column density (NH i < 1015 cm−2) Lyman α (Lyα) absorbers from the literature. The redshift-space correlation is found to be similar in strength to HIPASS galaxy self-clustering (correlation length s0,ag= 6 ± 4 h−1100 Mpc and s0,gg= 3.1 ± 0.5 h−1100 Mpc, respectively). In real space the cross-correlation is stronger than the galaxy auto-correlation (correlation length r0,ag= 7.2 ± 1.4 h−1100 Mpc and r0,gg= 3.5 ± 0.7 h−1100 Mpc, respectively) on scales from 1 to 10 h−1100 Mpc, ruling out the minihalo model for the confinement Lyα absorbers at the 99 per cent confidence level. Provided that the cause of the strong cross-correlation is purely gravitational, the ratio of correlation lengths suggest that absorbers are embedded in dark matter haloes with masses log(M/M⊙) = 14.2 h−1100, similar to those of galaxy groups. The flattening of the cross-correlation at separations less than ∼600 h−1100 kpc could correspond to the thickness of filaments in which absorbers are embedded. This work provides indirect statistical evidence for the notion that galaxy groups and large-scale filaments, particularly those that comprise gas-rich galaxies, are the dominant environments of low column density Lyα absorbers at z= 0.