Absorbers in the suburbs: HST views the local Lyα forest
نویسندگان
چکیده
منابع مشابه
Broadening of QSO Lyα forest absorbers
We investigate the dependence of QSO Lyα absorption features on the temperature of the absorbing gas and on the amplitude of the underlying dark matter fluctuations. We use high-resolution hydrodynamic simulations in cold dark matter dominated cosmological models. In models with a hotter intergalactic medium (IGM), the increased temperature enhances the pressure gradients between low and high d...
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We describe recent discoveries of low column density (NHI ≤ 10 cm) H I Lyα absorbers made with the Hubble Space Telescope (HST) which have allowed us a first look at gas in local intergalactic space between us and the “Great Wall”. Despite the mere 2.4m aperture of HST, these new observations allow us to detect absorbers with column densities, NHI ≈ 10 12.5 cm, as low as those found using Keck/...
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We create stacked composite absorption spectra from Hubble Space Telescope Faint Object Spectrograph data from four quasi-stellar objects to search for absorption lines in the extreme ultraviolet wavelength region associated with Lyα forest absorbers in the redshift range 1.6 < z < 2.9. We successfully detect O V λ630 in Lyα absorbers throughout the 1013 to 1016.2 cm−2 column density range. For...
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 کاملLyα 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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ژورنال
عنوان ژورنال: Proceedings of the International Astronomical Union
سال: 2004
ISSN: 1743-9213,1743-9221
DOI: 10.1017/s1743921304000250