منابع مشابه
The Low Column Density Lyman-alpha Forest
We develop an analytical method based on the lognormal approximation to compute the column density distribution of the Lyman-alpha forest in the low column density limit. We compute the column density distributions for six different cosmological models and found that the standard, COBE -normalized CDM model cannot fit the observations of the Lyman-alpha forest at z = 3. The amplitude of the flu...
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Lyα absorber correlations contain information about the underlying density distribution associated with a particular class of absorbers. As such, they provide an opportunity to independently measure the “bias” of the Lyman alpha forest, i.e. the relationship between H I column density and underlying dark matter density. In these proceedings we use hydrodynamic simulations to investigate whether...
متن کاملStructure in the Lyα Forest
The spatial distribution of Lyα forest absorption systems toward a group of 8, closely spaced QSOs has been analysed and evidence for large scale structure has been found at z = 2.8. Our technique is based on the first and second moments of the transmission probability density function which is capable of identifying and assessing the significance of regions of over-or underdense Lyα absorption...
متن کاملRadiative Transfer Effects on the Lyα Forest
Strong observational evidence for a fluctuating ultraviolet background (UVB) has been accumulating through a number of studies of the H I and He II Lyα forest as well as accurate IGM metallicity measurements. UVB fluctuations could arise both from the inhomogeneous distribution of the ionizing sources and/or from radiative transfer (RT) through the filamentary IGM. In this study we investigate,...
متن کاملThe Lyα Forest Around High Redshift Galaxies
Motivated by the relative lack of neutral hydrogen around Lyman Break Galaxies deduced from recent observations, we investigate the properties of the Lyα forest around high redshift galaxies. The study is based on improved numerical SPH simulations implementing, in addition to standard processes, a new scheme for multiphase and outflow physics description. Although on large scales our simulatio...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 1996
ISSN: 0004-637X
DOI: 10.1086/310366