From Science Daily, ICRAR's 27 May press release. The question here is to account for such (apparently) invisible mass as is not bound up in galaxies. So this is not Dark Matter, detectable precisely because it is clustering in galaxies. They're talking free baryons - that is, protons, otherwise known as "hydrogen". Also I think they were expecting to see more hydrogen (mostly) from the cosmic-background, than is today inferred from galaxies.
So they were looking at intergalactic space. This space is a near perfect vacuum - sparser even than interstellar. But it might bear (barely) enough gas, mostly hydrogen remember, to scatter light. That light should be emitted from as distant as possible, so scatter such that we can see it here. It also helps that they are confident in the Hubble Constant now.
A gamma-ray burst should do it, and that's what they've seen. Now the numbers add up, for baryonic matter. One more intergalactic dragon slain.
HUBBLE HOBBLING 11/6: Anyone claiming confidence in Hubble this year is a damned liar.
No comments:
Post a Comment