The X-Rays Thought to Prove What Makes Up Dark Matter Don’t, In Fact, Prove the Connection
Despite figuring out darkish matter is on the market, astrophysicists are nonetheless lacking one vital element. “We know where it is and how much of it there is, but we don’t know what it is,” says Ben Safdi, an astrophysicist at the University of Michigan.
Some assume this mysterious substance is manufactured from hypothetical subatomic particles known as sterile neutrinos. Unlike common neutrinos, which work together by way of each gravity and the weak nuclear power, sterile neutrinos would solely work together by way of gravity. And that appears to be the very same guidelines of engagement that darkish matter follows.
For this motive, astrophysicists since 2014 have sought the X-ray alerts that may be produced if sterile neutrinos had been decaying into regular matter as hypothesized. If such X-ray signatures had been discovered, it might strongly counsel sterile neutrinos are a (if not the) elusive supply of darkish matter.
But after sifting by means of 20 years’ value of knowledge from the darkest, blackest areas of our personal galaxy in the hunt for that particular X-ray sign, Safdi and his analysis workforce noticed nothing.
That means there may be at the moment no experimental proof that darkish matter is manufactured from the sterile neutrino, Safdi and his workforce concluded of their work, revealed in Science.
“We were disappointed. This is not the result we were hoping for,” Safdi says. Their outcomes don’t imply that sterile neutrinos aren’t the supply of darkish matter — simply that this specific X-ray is not going to show the connection. So now it’s again to the drafting board to see what else may hyperlink the two collectively.
Taking a Closer Look
Though different efforts to hyperlink darkish matter to these alerts had checked out faraway galaxies, Safdi and his co-authors determined to look nearer to residence.
“The leap we made was that if [the X-ray signal is issuing] there, then it should also be [issuing] around our own galaxy.” The Milky Way, the place our photo voltaic system resides, is surrounded by the mysterious substance, Safdi says. The workforce searched the absolute darkest, blankest parts of our galaxy — components which can be presumably solely darkish matter — for the X-ray sign. But no such X-ray appeared in the workforce’s information.
It’s doable this X-ray sign appeared in different darkish matter searches as a type of contaminant, Safdi says. Looking at galaxies distant means interference from gases, stars and different cosmic supplies find yourself in the information. Dark matter data from our personal galaxy is extra pure. “We were looking for dark matter radiation on top of nothing,” Safdi says.
A New Approach
Safdi and his workforce assume that perhaps other forms of X-rays — ones with totally different wavelengths — may nonetheless show that sterile neutrinos make up darkish matter. They’re now making use of their similar analysis idea to these totally different X-rays to see if these is likely to be radiating from the blackest areas of the Milky Way.
“We now have this powerful method we can apply to this data,” Safdi says, “And, who knows? Maybe we’ll find evidence for dark matter.”