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Evolution of the intergalactic medium - What happened during the epoch z = 3-10?An attempt is made to model consistently the thermal and dynamic history of the intergalactic medium (IGM) from the era of reheating (z = 10-5) to the present, and to provide a unified explanation for the origin of ordinary galaxies, blue compact objects, and Lyman-alpha clouds. The evolution of the intergalactic gas is analyzed, treating the IGM as perfectly homogeneous at every epoch and taking into account radiative and Compton cooling, adiabatic cooling, shock heating, and heating produced by the diffuse UV flux. It is suggested that the IGM must have been heated to higher than a 10 to the 6th K by shock heasting caused either by explosions of pregalactic objects or expanding voids. The formation of intergalactic clouds by fragmentation of the resulting shells and the subsequent collapse of the shells to form galaxies are studied. An attempt is made to determine model parameters on the basis of an analysis of Lyman-alpha absorption lines.
Document ID
19860046015
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ikeuchi, S. (Princeton Univ. Observatory NJ, United States)
Ostriker, J. P. (Princeton University Observatory, NJ, United States)
Date Acquired
August 12, 2013
Publication Date
February 15, 1986
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 301
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAGW-765
CONTRACT_GRANT: NSF AST-80-22785
Distribution Limits
Public
Copyright
Other