'Hugely Important' Discovery May Finally Explain Dark Matter

Wednesday, 20 December 2017 - 11:18AM
Space
Astronomy
Wednesday, 20 December 2017 - 11:18AM
'Hugely Important' Discovery May Finally Explain Dark Matter
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Image credit: NASA
Whenever you feel like science has gotten a pretty good understanding of how things work in the universe, it's important to remember that, according to NASA, "everything ever observed with all of our instruments" (all the planets, all the stars, all the galaxies and dust clouds and asteroid belts and black holes) adds up to about 5 percent of all the matter in the universe. The other 85-95 percent is made up of two substances that we have little to no idea about: dark energy and dark matter.

Dark matter is still hypothetical—no one's ever observed it directly because it doesn't appear to absorb or emit light, and it doesn't even interact with "normal" matter in the usual ways. Because of this, dark matter has become something of a shorthand for "here be dragons" when scientists come across something that doesn't seem to have a rational answer. One such instance is the curious case of Chandra X-ray Observatory and the Perseus galaxy cluster.

Back in 2014, NASA's Chandra X-Ray Observatory found a strange spike in X-rays with an energy of 3.5 kiloelectron volts (KeV) coming from Perseus. The reason for this spike couldn't be explained by anything scientists knew about astronomical objects, so a team of astronomers led by Esra Bulbul put forth a hypothesis that the spike in X-rays was caused by the decay of "sterile neutrinos," a hypothetical particle that's been suggested in the past as the true identity of dark matter.

If these X-rays turned out to be sterile neutrinos (and those neutrinos turned out to be dark matter), then Bulbul's team would be the first to ever pick up direct evidence of dark matter itself.

However, Joseph Conlon, one of the leads on a new study following up on Bulbul's observations, admits it's a "long shot" (as Bulbul himself said): "We expect that this result will either be hugely important or a total dud. I don't think there is a halfway point when you are looking for answers to one of the biggest questions in science."

The new study came about because observations by other teams didn't pick up on this anomalous spike in X-rays.

This caused doubt that the Chandra Observatory had discovered anything significant at all, but after re-examining the conditions in the Perseus cluster, Conlon proposed that the angles of observation used by researchers may have changed the results they were getting.

The co-author on the study, Nicholas Jennings, admitted there's a lot of complications in this discovery, but the payoff could be huge: "This is not a simple picture to paint, but it's possible that we've found a way to both explain the unusual X-ray signals coming from Perseus and uncover a hint about what dark matter actually is."
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'Hugely Important' Discovery May Finally Explain Dark Matter
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