Scientists at Monash University in Australia have found that collisions of neutron stars cannot lead to an abundance of heavy elements in the universe. Previously, this process was considered the main cause of the formation of metals such as gold, silver, thorium and uranium. The publication Science Alert reports on the refutation of the established ideas about the appearance of atoms.
For elements heavier than iron to arise, an r-process is required, also called the fast neutron capture process. It takes place during supernova explosions, when, in the course of nuclear reactions, atomic nuclei begin to capture neutrons, without having time to decay. A collision of neutron stars can trigger the r-process, however, for the observed pattern of the distribution of heavy elements in the Universe, some minimum collision frequency of neutron stars is required.
Researchers have built models of the evolution of chemical elements in the Universe, taking into account the frequency of nucleosynthesis events. It turned out that collisions of neutron stars cannot explain the presence of heavy elements either in the early Universe or in our days. Instead, a special type of supernovae could be the source of atoms: magnetorotational supernovae.
Magnetically rotating supernovae occur when the core of a massive, rapidly rotating star with a strong magnetic field collapses. This process is energetic enough to trigger rapid neutron capture. Magnetically rotating stars must make up a fairly small percentage of those luminaries that have 25-50 solar masses to explain the excess of heavy elements.
