Model offers explanation for universe's most powerful magnets

Oct. 10 (UPI) -- With the help of computer simulations, scientists have come up with an explanation for the formation of the strongest magnets in the universe, magnetars.

Models suggest stellar mergers can produce strong magnetic fields. When the magnetic star produced by a merger dies, a magnetar can form. Magnetars are neutron stars -- collapsed stellar cores -- with extremely powerful magnetic fields.

The sun features an outer layer of convective activity that produces strong magnetic fields, but most massive stars are without this feature.

"Even though massive stars have no such envelopes, we still observe a strong, large-scale magnetic field at the surface of about ten percent of them," Fabian Schneider, researcher with the Center for Astronomy at Heidelberg University in Germany, said in a news release.

Scientists have previously hypothesized that stellar mergers could explain the ten percent that boast large magnetic fields.

"But until now, we weren't able to test this hypothesis because we didn't have the necessary computational tools," said Sebastian Ohlmann from the computing center at the Max Planck Society in Garching.

To test the hypothesis, researchers used a sophisticated stellar simulation called the AREPO code, run on a cluster of powerful computers, to analyze Tau Scorpii, a magnetic star located 500 light-years from Earth.

Scientists had previously determined that Tau Scorpii is a blue straggler, which are produced by the merging of two stars. The simulations showed that the turbulence produced by the merger process can yield powerful magnetic fields.

The latest findings, published this week in the journal Nature, suggest roughly 10 percent of the stars in the Milky Way form similarly to Tau Scorpii -- a rate in agreement with the observed population of magnetic massive stars.