Journal Article

The Dark Ages of the Universe and hydrogen reionization

Aravind Natarajan and Naoki Yoshida

in Progress of Theoretical and Experimental Physics

Published on behalf of The Physical Society of Japan

Volume 2014, issue 6
Published online June 2014 | e-ISSN: 2050-3911 | DOI:

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One of the milestones in cosmic history is the formation of the first luminous objects and hydrogen reionization. The standard theory of cosmic structure formation predicts that the first generation of stars were born about a few hundred million years after the Big Bang. The dark Universe was then lit up once again, and eventually filled with ultraviolet photons emitted from stars, galaxies, and quasars. The exact epoch of the cosmic reionization and the details of the process, even the dominant sources, are not known, except for the fact that the Universe was reionized early on. Signatures of reionization are expected to be imprinted in the cosmic microwave background (CMB) radiation, especially in its large-scale polarization. Future CMB experiments, together with other probes such as the H i 21 cm surveys, will provide rich information on the process of reionization. We review recent studies on reionization. The implications from available observations over a wide range of wavelengths are discussed. Results from state-of-the-art computer simulations are presented. Finally, we discuss the prospects for exploring the first few hundred million years of the cosmic history.

Keywords: E28; E55; E63

Journal Article.  8364 words.  Illustrated.

Subjects: Galaxies ; Cosmology

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