Comparing Simulations and Observations of the Lyα Forest. I. Methodology
نویسندگان
چکیده
منابع مشابه
Lyα ABSORBER CORRELATIONS AND THE “BIAS” OF THE Lyα FOREST
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...
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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 کاملPhysical Properties, Baryon Content, and Evolution of the Lyα Forest: New Insights from High Resolution Observations
We present a study of the Lyα forest at z . 0.4 from which we conclude that at least 20% of the total baryons in the universe are located in the highly-ionized gas traced by broad Lyα absorbers. The cool photoionized low-z intergalactic medium (IGM) probed by narrow Lyα absorbers contains about 30% of the baryons. We further find that the ratio of broad to narrow Lyα absorbers is higher at z . ...
متن کاملGalactic winds and the Lyα forest
We study the effect of galactic outflows on the statistical properties of the Lyα forest and its correlation with galaxies. The winds are modelled as fully ionised spherical bubbles centered around the haloes in an N-body simulation of a ΛCDM model. The observed flux probability distribution and flux power spectrum limit the volume filling factor of bubbles to be less than 10%. We have compared...
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,...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2002
ISSN: 0004-637X,1538-4357
DOI: 10.1086/338033