A team of German-British astrophysicists has recently solved the riddle- How do some neutron stars become the strongest magnets in the Universe?
By using large computer simulations, they determined how the merger of two stars creates strong magnetic fields. If such stars explode in supernovae, magnetars could result.
Dr. Fabian Schneider from the Centre for Astronomy of Heidelberg University said, “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. Although such fields were already discovered in 1947, their origin has remained elusive so far.”
Almost before a decade ago, scientists suggested that strong magnetic fields are produced when two stars collide. But, scientists weren’t able to test this hypothesis because we didn’t have the necessary computational tools.
In this new study, scientists used the AREPO code, a highly dynamic simulation code running on compute clusters of the Heidelberg Institute for Theoretical Studies (HITS), to explain the properties of Tau Scorpii (τ SCO), a magnetic star located 500 light-years from Earth.
In 2016, Fabian Schneider and Philipp Podsiadlowski from the University of Oxford realized that τ Sco is a so-called blue straggler. Blue stragglers are the product of merged stars.
Prof. Dr. Philipp Podsiadlowski said, “We assume that Tau Scorpii obtained its strong magnetic field during the merger process. Through its computer simulations of τ Sco, the German-British research team has now demonstrated that strong turbulence during the merger of two stars can create such a field.”
Dr. Schneider said, “Stellar mergers are relatively frequent: Scientists assume that about ten percent of all massive stars in the Milky Way are the products of such processes. This is in good agreement with the occurrence rate of magnetic massive stars. Astronomers think that these very stars could form magnetars when they explode in supernovae.”
Prof. Dr. Friedrich Röpke from HITS said, “This may also happen to τ Sco when it explodes at the end of its life. The computer simulations suggest that the magnetic field generated would be sufficient to explain the powerful magnetic fields in magnetars.”