A few hundred thousand years after the big bang, the Universe was a-hummin’ and a-jigglin’ with a plasma of hydrogen and helium nuclei as well as electrons. As the universe cooled, the electrons combined with the nuclei to form neutral atoms, giving off photons in the process. These photons are what we see as the cosmic background radiation.

This so-called cosmic re-ionization was significant because it allowed light from the first quasars and galaxies to travel through the universe for the first time. (Prior to that the light was absorbed by the plasma.) And in 2001, astronomers at Caltech spotted relics from this period in the universe for the first time.

But Nickolay “Gnu” Gnedi at the Kavli Institute for Particle Physics at the University of Chicago says he’s found a problem. There ought to be just enough photons in the background radiation to account for all them atoms in the early universe, right? Well, Gnu has been a-countin’ and says there ain’t enough. He bases his argument on observational data and numerical simulations

The work raises an interestin’ possibility. If we can’t see enough photons from all the galaxies, quasars and dwarf galaxies we been lookin’ at, then there’s gotta be other things out there which we ain’t seein’. Either that or Gnu Gnedi has his numbers wrong.

Ref: arxiv.org/abs/0709.3308 : Are There Enough Ionizing Photons to Reionize the Universe by z=6?

This entry was posted on Friday, October 5th, 2007 at 12:01 am and is filed under Stars in their eyes, The good ol' days. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.