The study of dwarf galaxies, stuffed with heavy elements, allowed the scientists to determine that the main sources of gold may be dying neutron stars.
Initially, in the universe it was only the lightest atoms, hydrogen with small amounts of helium. The entire set of elements up to iron emerged from them as a result of thermonuclear reactions taking place – and continue to occur – in the depths of many generations of stars. However, the birth of heavier elements, including gold or uranium, requires more severe conditions, according to Naked Science.
More than half a century ago, theorists have described a possible mechanism of their formation. This r-process, in which the free-moving neutrons are captured by nuclei of iron atoms accumulate in it. Some of the neutrons may then lose an electron, turning into protons and forming an increasingly heavy nucleus. Calculations show that a seizure should occur quickly – faster than the decay unstable isotopes of iron with a high number of neutrons. This requires special conditions of occurrence r-process, and it is believed that in space it can be implemented just before the explosion a huge supernova or in the shock wave of the explosion at the confluence of the pair is incredibly dense neutron stars and other very extreme circumstances.
This pattern is common in astrophysics, but remains theoretical in many ways. In particular, what kind of contribution to the content of the universe these elements make supernovae, and what – the merger of neutron stars remains a topic of debate. These disputes were developed as a result of new observations of the dwarf galaxy Grid II, open only about a year ago. Grid II – one of the many small satellites of the Milky Way, and is just 98 000 light-years from Earth. And it is packed with elements heavier than iron.
Noticing this, astronomers were able from the Kavli Institute, used Location Chile Observatory telescopes Las Campas. Watching seven of the nine biggest and brightest stars Grid II, so they have noted an abnormally high content of elements heavier than iron. This is a very unusual feature sharply distinguishes Grid II in the background of the neighboring dwarf galaxies. In an article published by the journal Nature, the authors put forward the assumption that what is powerful event in the distant past Nets II could saturate it with such elements.
The fact that the number and relative composition of heavy elements, born of a supernova explosion or the merger of neutron stars, can vary. The explosion of the star mass is eight times the solar mass will gold around the Moon, – explains Professor, University of California at Santa Cruz. The merger of neutron stars will produce gold as much weighs all Jupiter. Discovered by scientists the amount of heavy elements in the Grid II shows exactly neutron stars as the main source of such nuclei. At least in dwarf galaxies.