Where did the gold come from? Who and when was created? Last year, an astrophysical observation helped find the key to the answer. Gold preceded the formation of our planet. People appreciate gold bars and diamonds, but these jewels are different. Diamond comes from simple coal, whose atomic structure is changing due to the powerful pressure of the earth's crust. But no forces in the earthly mantle are able to create gold. So the alchemists in vain began to extract it from lead.
But on our planet there is this metal. It can be found in the deep core, as well as in the crust, where it is mined. It is interesting that in the core it was at the very beginning, but it went to the crust after the creation of the planet. This was due to a meteor strike that attacked Earth (and the Moon) 3.8 billion years ago.
Formation of heavy elements
But how is gold created in the universe? Such heavy elements are partially created by the process s (s - slow), acting in the core of the AGB stars (less than 10 solar masses). The second half is the r process (r is fast).
The discovery was made on August 17, 2017, but it is important to know the background. More than half a century in the scientific community was dominated by the idea that the r-process occurred during the final explosion of massive stars. Indeed, the formation of light elements (up to iron) needs nuclear reactions. For heavier elements, you have to add energy or choose specific paths - s and r processes. Scientists believed that the r-process can be realized in the ejected substance due to the explosion and is involved in the distribution of material in the interstellar medium. It seems that everything is simple, but when modeling supernovae, scientists are faced with difficulties. After 50 years, they only began to delve into the mechanism and most simulations do not provide the physical conditions for the r-process.
This is an artistic vision and an accelerated version of the first 9 days of the kilon (merging of two neutron stars). It resembles the one that was observed on August 17 (GW170817). In the phase of convergence, gravitational waves are painted in a light blue color, and after fusion they release a jet (orange), generating a gamma-ray burst. The ejected material creates the original UV light (violet), and then white in optics and IR (red).
Merging of neutron stars
In recent decades, researchers have begun to seriously think about alternative options for creating heavy elements. They focused on neutron stars. These are large reservoirs of neutrons, occasionally emitting material. The strongest release occurs during the merge period in a binary system.
Periodically, such events occur in space, and on August 17 one of them was noticed. It was the radiation of a gravitational wave, reaching its highest point a second before the final merger of stars and the explosion of high-energy light. These bursts were observed constantly, but only with the advent of LIGO and Virgo were they able to photograph them. After detecting the simultaneous activation of gravitational waves and a gamma-ray burst on August 17, scientists sent telescopes for continuous surveillance. They noticed kilonic and confirmed the creation of elements heavier than iron. It was also possible to estimate the frequency of the phenomenon and the amount of discarded material.
New window to the Universe
An absolutely new view of space was provided by Galileo with his telescope. But the creation of LIGO and Virgo allowed to “hear” the most powerful events in the Universe, which opens the doors for scientific research to astronomers, astrophysicists, nuclear physicists and nuclear physicists. In addition, Japan and India are currently developing to create new interferometers that will increase the existing capabilities of scientists.
