Redshifted 21 cm Emission from Minihalos before Reionization
نویسندگان
چکیده
منابع مشابه
Redshifted 21 cm Emission From the Pre-Reionization Era I. Mean Signal and Linear Fluctuations
We use cosmological simulations of reionization to predict the possible signal from the redshifted 21 cm line of neutral hydrogen in the pre-reionization era and to investigate the observability of this signal. We show that the separation of the mean (global) signal over the whole sky from the known foreground contamination may be feasible, but very challenging. In agreement with previous studi...
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We study the absorption along lines of sight toward high-z radio sources caused by the 21 cm transition of neutral hydrogen in the intergalactic medium (IGM) before reionization. Using semi-analytic methods, we compute the number density of observable features caused by both “minihalos” (bound objects that are unable to cool efficiently because of their small virial temperatures) and protogalac...
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Many models of early structure formation predict a period of heating immediately preceding reionization, when X-rays raise the gas temperature above that of the cosmic microwave background. These X-rays are often assumed to heat the intergalactic medium (IGM) uniformly, but in reality will heat the gas more strongly closer to the sources. We develop a framework for calculating fluctuations in t...
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The H atoms inside minihalos (i.e. halos with virial temperatures Tvir ≤ 10K, in the mass range roughly from 10M⊙ to 10 M⊙) during the cosmic dark ages in a ΛCDM universe produce a redshifted background of collisionally-pumped 21-cm line radiation which can be seen in emission relative to the cosmic microwave background (CMB). Previously, we used semi-analytical calculations of the 21-cm signal...
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We study the statistical properties of the cosmological 21 cm signal from both the intergalactic medium (IGM) and minihalos, using a reionization simulation that includes a self–consistent treatment of minihalo photoevaporation. We consider two models for minihalo formation and three typical thermal states of the IGM – heating purely by ionization, heating from both ionizing and Lyα photons, an...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2006
ISSN: 0004-637X,1538-4357
DOI: 10.1086/508448