When George Fraser passed away earlier this year, he had already done several lifetimes worth of work. As director of the University of Leicester’s Space Research Center, he was a pioneer in x-ray astronomy—the header graphic above, by the way, is an x-ray image of the Sun—and his decades of work revealed pieces of the cosmos we had never seen before. But it may be his very last paper, just published last week, that represents his most game-changing contribution to the field of astronomy. Because George Fraser, and his colleagues at Leicester, may very well have discovered what dark matter is made of. And if they did, they discovered it by looking at what is, from our vantage point, the very brightest part of the observable universe.
The Leicester press office reports:
In a study being published on Monday 20 October in the Monthly Notices of the Royal Astronomical Society, the University of Leicester scientists describe their finding of a signal which has no conventional explanation …
“The X-ray background – the sky, after the bright X-ray sources are removed – appears to be unchanged whenever you look at it,” explained Dr. Andy Read, also from the University of Leicester Department of Physics and Astronomy and now leading the paper. “However, we have discovered a seasonal signal in this X-ray background, which has no conventional explanation, but is consistent with the discovery of axions” …
As Professor Fraser explains in the paper: “It appears plausible that axions – Dark Matter particle candidates – are indeed produced in the core of the Sun and do indeed convert to X-rays in the magnetic field of the Earth.”
This is potentially huge. 85% of the matter in the observable universe is made of heretofore unobservable stuff, and any steps we can take towards observing it will change our understanding of the cosmos forever. There are, of course, several caveats we ought to keep in mind:
- Axions are hypothetical particles. If the Leicester study can be vetted and replicated, this might be the first time we’ve ever seen the things. (I say might because a study from last year suggests that we might have been observing axionic dark matter in slightly different contexts for years without realizing it.)
- The Leicester data might prove less persuasive under scrutiny, much as the BICEP2 gravitational wave discovery did earlier this year. Science can be brutal like that.
- We have no reason to believe that dark matter is composed of only one type of exotic particle. It’s entirely possible that the matter we can’t observe is every bit as complex and diverse as the matter we can.
But what an interesting thing to find, and what an interesting place to find it.