11
November 2004
Hubble bubble?
Most of the neutral atomic hydrogen left over from the Big Bang was ionized by the first generation of galaxies when the Universe was only a billion years old. The ionized bubbles created by clustered groups of galaxies grew and eventually overlapped. Recent spectroscopic observations of the most distant known quasars at a redshift of z = 6 are now shown to be consistent with a characteristic size of about 10 megaparsecs for these bubbles during the final overlap stage, equivalent to about 0.5° on the sky. This has direct implications for the design of the next generation of low-frequency radio observations, when the goal will be the detection of the 21-cm emission expected to represent the end of the 'reionization' epoch.
A characteristic size of ~10 Mpc for the
ionized bubbles at the end of cosmic reionization
J. STUART B. WYITHE & ABRAHAM LOEB
Nature 432, 194–196 (2004); doi:10.1038/nature03033
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