By Ron Cowen
Peering far back in time, two teams of astronomers say they’ve found some of the universe’s earliest galaxies. The findings suggest that less than a billion years after the Big Bang, some galaxies were already minting the equivalent of several suns a year, a prodigious rate of star formation.
The data also hint that the average density of these galaxies is only about one-sixth that of similarly bright star-forming galaxies observed roughly a half-billion years later in cosmic history.