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X-ray clusters in a cold dark matter + lambda universe: A direct, large-scale, high-resolution, hydrodynamic simulationA new, three-dimensional, shock-capturing, hydrodynamic code is utilized to determine the distribution of hot gas in a cold dark matter (CDM) + lambda model universe. Periodic boundary conditions are assumed: a box with size 85/h Mpc, having cell size 0.31/h Mpc, is followed in a simulation with 270(exp 3) = 10(exp 7.3) cells. We adopt omega = 0.45, lambda = 0.55, h identically equal to H/100 km/s/Mpc = 0.6, and then, from the cosmic background explorer (COBE) and light element nucleosynthesis, sigma(sub 8) = 0.77, omega(sub b) = 0.043. We identify the X-ray emitting clusters in the simulation box, compute the luminosity function at several wavelength bands, the temperature function and estimated sizes, as well as the evolution of these quantities with redshift. This open model succeeds in matching local observations of clusters in contrast to the standard omega = 1, CDM model, which fails. It predicts an order of magnitude decline in the number density of bright (h nu = 2-10 keV) clusters from z = 0 to z = 2 in contrast to a slight increase in the number density for standard omega = 1, CDM model. This COBE-normalized CDM + lambda model produces approximately the same number of X-ray clusters having L(sub x) greater than 10(exp 43) erg/s as observed. The background radiation field at 1 keV due to clusters is approximately the observed background which, after correction for numerical effects, again indicates that the model is consistent with observations.
Document ID
19950037341
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Cen, Renyue
(Princeton Univ. Princeton, NJ, United States)
Ostriker, Jeremiah P.
(Princeton Univ. Princeton, NJ, United States)
Date Acquired
August 16, 2013
Publication Date
July 1, 1994
Publication Information
Publication: The Astrophysical Journal, Part 1
Volume: 429
Issue: 1
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A68940
Funding Number(s)
CONTRACT_GRANT: NSF AST-91-08103
CONTRACT_GRANT: NSF ASC-93-18185
CONTRACT_GRANT: NAGW-2448
Distribution Limits
Public
Copyright
Other

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