A nearby supernova may end the search for dark matter

Nov. 22 () –

The search for the universe’s dark matter could end tomorrow if a supernova occurs nearby and a little luckaccording to Berkeley astrophysicists.

The nature of dark matter has eluded astronomers for 90 years, since it was discovered that 85% of the matter in the universe is not visible through our telescopes. The most likely candidate for dark matter today is the axiona light particle that researchers around the world are desperately trying to find.

New research published in Physical Review Letters determines that the axion could be discovered within seconds after the detection of gamma rays from a nearby supernova explosion. Axions, if they exist, would be produced in copious quantities during the first 10 seconds after core collapse from a massive star into a neutron star, and those axions would escape and transform into high-energy gamma rays in the star’s intense magnetic field.

10 PERCENT CHANCE

Such detection is possible today only if the only gamma-ray telescope in orbit, the Fermi Gamma-ray Space Telescope, points in the direction of the supernova at the time of its explosion. Given the telescope’s field of view, that represents about a one in ten chance.

However, a single gamma ray detection would determine the mass of the axion, in particular the so-called QCD axion, in a wide range of theoretical massesincluding mass ranges now being explored in experiments on Earth. However, the lack of a detection would eliminate a wide range of potential masses for the axion and make most current searches for dark matter irrelevant.

The problem is that for the gamma rays to be bright enough to detect, the supernova has to be nearby (within our Milky Way galaxy or one of its satellite galaxies). and nearby stars explode only on average every few decades. The last nearby supernova was in 1987 in the Large Magellanic Cloud, one of the satellites of the Milky Way. At the time, a now-inactive gamma-ray telescope, the Solar Maximum Mission, was pointed in the direction of the supernova, but was not sensitive enough to detect the predicted intensity of the gamma rays, according to the NASA team’s analysis. UC Berkeley.

“If we saw a supernova, like supernova 1987A, with a modern gamma-ray telescope, we would be able to detect or rule out this QCD axion, this very interesting axion, in much of its parameter space, essentially the entire parameter space that cannot be analyzed in the laboratory, and much of the parameter space that can be analyzed in the laboratory as well,” he said in a statement Benjamin Safdi, associate professor of physics at UC Berkeley and senior author of the study. “And it would all happen in 10 seconds.”

However, researchers fear that when the long-awaited supernova explodes in the nearby universe, we are not prepared to see the gamma rays produced by axions. Scientists are now talking to colleagues who build gamma-ray telescopes to evaluate the feasibility of launching one or a fleet of these telescopes to cover 100% of the sky 24 hours a day, 7 days a week and be sure to capture any burst of gamma rays. They’ve even proposed a name for their all-sky gamma-ray satellite constellation: the GALactic AXion Instrument for Supernovae, or GALAXIS.

“I think all of us on this paper are stressed about the possibility of there being a next supernova before we have the proper instrumentation,” Safdi said. “It would be a real shame if a supernova exploded tomorrow and we lost the opportunity to detect the axion; I might not come back for another 50 years.