1993/07/31 by Max Tegmark, Joseph Silk, Alain Blanchard · 60 citations
Physics and Astronomy · #Background radiation #COSMIC cancer database #Cosmic background radiation #Cosmic microwave background #Cosmology and Gravitation Theories #Dark Ages #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Intergalactic medium #Intergalactic travel #Photoionization #Reionization #astro-ph
paper · pdf · doi:10.1086/173579
published in The Astrophysical Journal 420, 484 (IOP Publishing) · 32 pages, incl 10 figures. Stone-age postscript replaced by LATeX. Latest version at http://www.sns.ias.edu/~max/reion.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/reion.html (faster from Europe) or from [email protected]
openalex publication_date 1994/01/01 · arxiv created 1996/09/08 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Early photoionization of the intergalactic medium is discussed in a nearly model-independent way, in order to investigate whether early structures corresponding to rare Gaussian peaks in a CDM model can photoionize the intergalactic medium sufficiently early to appreciably smooth out the microwave background fluctuations. We conclude that this is indeed possible for a broad range of CDM normalizations and is almost inevitable for unbiased CDM, provided that the bulk of these early structures are quite small, no more massive than about 108^ Msun_. Typical parameter values predict that reionization occurs around z = 50, thereby suppressing fluctuations on degree scales while leaving the larger angular scales probed by COBE reasonably unaffected. However, for nonstandard CDM, incorporating mixed dark matter, vacuum density, or a tilted primordial power spectrum, early reionization plays no significant role.