Astrobods have been searching for dark matter for a decade or so now. And despite it filling the known Universe, there’s been no sign of the stuff .
But could it be that we’ve been staring at it all along without knowing what we’ve been looking at?
That’s the claim of a couple of theorists in North America. They say that dark matter is in the form of large nuggets of dense quark matter or quark anti-matter and that this could explain a number of mysterious observations that astronomers have been making in recent years.
Michael Forbes of University of Washington, in Seattle and Ariel Zhitnitsky from the University of British Columbia in Vancouver say these nuggets float around in the form of tiny 10 ton lumps and would emit thermal radiation that should be straightforward to measure.
And sure enough, astronomers have been puzzling over a number of unexplained bands of radiation coming from the center of our galaxy that have been picked up by orbiting telescopes in recent years. The gamma ray observatory Integral has spotted a mysterious 511 KeV glow, the Compton gamma ray observatory has found an unexplained signal between 1- 20 MeV, the Chandra x-ray telescope sees a diffuse keV x-ray emission all over the place and WMAP has detected an excess of GHz microwave radiation from the inner core of the galaxy called the WMAP haze.
All this can be explained by quark nuggets, say the pair of astronomers. Interestingly, they also make a number of predictions about the nature and distrbution of the radiation emitted by nuggets that should be straightforward to test. So unlike most dark matter theories, this one will stand or fall relatively quickly.
The theory also explains why none of the detectors on Earth have spotted these nuggets–the nuggets are distributed too sparsely to have been seen yet.
But when one of these ten ton beauties does come floating by, we’re not likely to miss its impact.
Ref: arxiv.org/abs/0802.3830: WMAP Haze: Directly Observing Dark Matter?