Dark galaxies of the early Universe spotted for the first time (light, bright)

[Brian.Pearson]

"Our approach to the problem of detecting a dark galaxy was simply to shine a bright light on it." explains Simon Lilly (ETH Zurich, Switzerland), co-author of the paper. "We searched for the fluorescent glow of the gas in dark galaxies when they are illuminated by the ultraviolet light from a nearby and very bright quasar. The light from the quasar makes the dark galaxies light up in a process similar to how white clothes are illuminated by ultraviolet lamps in a night club." [1]

[Glitch]

I was just reading about that, from a different source.

BBC News - Seeing in the dark

While I consider the new method for discovering dark galaxies exciting, I do have an issue with them calling it "the early Universe." A redshift of z=2.4 is around 11 billion light years away, or 2.7 billion years after the Big Bang. That is not the "early" universe, that is the "intermediate" universe.

For "the early Universe" one needs to start with at least reionization, which is theorized to have been completed by around 150 million years after the Big Bang. It is also theorized that the first galaxies formed some 300 million years after the Big Bang. That would put those objects somewhere between a redshift of 10 < z > 20. If it is not redshifted by at least z~10, it cannot be construed to be "the early Universe."