Han-Seek Kim, J. Stuart B. Wyithe, Sudhir Raskutti, C. G. Lacey
The measurement of the power spectrum of redshifted 21cm fluctuations from neutral hydrogen during the Epoch of Reionization represents an important observational goal for modern cosmology. The aims of these experiments are to measure the epoch and duration of reionization, and to learn about the properties of the first galaxies. The structure of reionization, and hence the observed power spectrum are known to be sensitive to the astrophysical properties of the galaxies that drove reionization. Thus, detailed measurements of the 21cm power spectrum and its evolution could lead to measurements of the properties of early galaxies that are otherwise inaccessible. In this paper, we make a first attempt to connect the details of the 21cm power spectrum with realistic models for galaxy formation. We combine the semi-analytic GALFORM model for high redshift sources implemented within the Millennium dark matter simulation, with a semi-numerical scheme to describe the resulting ionization structure. Semi-analytic models based on the Millennium Simulation are limited to halo masses greater than ~10^{10}Msolar at z>6, and as a result the modelling is sensitive to astrophysics that is relevant for relatively large galaxies. We show that the details of supernova feedback affect the slope and amplitude of the 21 cm power spectrum, and that measurements of these quantities would be sufficient to determine the level at which supernova feedback operated in high redshift galaxies.
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http://arxiv.org/abs/1203.3598
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