1999/06/17 by M. E. Machacek, M. Macháček, G. L. Bryan +11 · 8 citations
Mathematics · Physics and Astronomy · #Amplitude #Astrophysics #Astrophysics and Star Formation Studies #Computational physics #Cosmology and Gravitation Theories #Distribution (mathematics) #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Geometry #Mathematics #Meteorology #Opacity #Optical depth #Optics #Physics #Range (aeronautics) #Redshift #Scaling #Statistical physics #astro-ph
paper · pdf · doi:10.1086/308551
37 pages, 21 figures, submitted to ApJ
arxiv created 1999/06/17 · openalex publication_date 2000/03/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the properties of the Lyα forest as predicted by numerical simulations for a range of currently viable cosmological models. This is done in order to understand the dependencies of the forest on cosmological parameters. Focusing on the redshift range from 2 to 4, we show that (1) most of the evolution in the distributions of optical depth, flux, and column density can be understood by simple scaling relations; (2) the shape of optical depth distribution is a sensitive probe of the amplitude of density fluctuations on scales of a few hundred kpc; and (3) the mean of the b distribution (a measure of the width of the absorption lines) is also very sensitive to fluctuations on these scales and decreases as they increase. We perform a preliminary comparison to observations, where available. A number of other properties are also examined, including the evolution in the number of lines, the two-point flux distribution, and the He II opacity.