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Lyman-alpha clouds as a relic of primordial density fluctuationsPrimordial density fluctuations are studied using a CDM model and primordial clouds some of which are expanding, driven by pressure gradients created when the medium is photionized, and some of which are massive enough to continue collapsing in spite of the pressure. Normalization of CDM models to the clustering properties on large scales are used to predict the parameters of collapsing clouds of subgalactic mass at early epochs. It is shown that the abundance and dimensions of these clouds are comparable to those of the Lyman-alpha systems. The evolutionary history of the clouds is computed, utilizing a spherically symmetric hydrodynamics code with the dark matter treated as a collisionless fluid, and the H I column density distribution is evaluated as a function of N(H I) and redshift. The observed cloud parameters come out naturally in the CDM model and suggest that Lyman-alpha clouds are the missing link between primordial density fluctuations and the formation of galaxies.
Document ID
19880038074
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Bond, J. R.
(Toronto, University Canada)
Szalay, A. S.
(NASAFermi National Accelerator Laboratory, Batavia, IL; Eotvos Lorand Tudomanyegyetem Budapest, Hungary)
Silk, J.
(California, University Berkeley, United States)
Date Acquired
August 13, 2013
Publication Date
January 15, 1988
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 324
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
88A25301
Distribution Limits
Public
Copyright
Other

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