While elements lighter than iron are formed in the cores of ordinary stars, heavy elements require much more energy. So, MIT scientists decided to search for sources of gold, platinum, and other elements in the Universe. It turns out neutron star collisions are a key source of gold in the universe.
The Big Bang Gave Birth to Several Chemical Elements
Several of the lightest chemical elements were formed during the Big Bang. Most of the common elements, that are lighter than iron, are formed inside stars in form of stellar fusion reactions ashes. The heaviest elements are more complicated. We know that extreme events in the Universe are involved in their origin, but the details of this process are still unclear.
US experts at the Massachusetts Institute of Technology (MIT) and the University of New Hampshire have investigated two possible sources of heavy elements in the Universe – neutron star collisions and neutron star-black hole collisions. Both sources undoubtedly produce heavy elements, but the question is which is more significant.
Gold Source in the Universe
Astronomer and astrophysicist Hsin-Yu Chen of MIT has found that, over at least the last 2.5 billion years, multiple heavy elements, such as gold or platinum, have been produced in the Universe by the collisions of pairs of neutron stars. Neutron star-black hole collisions have produced significantly fewer such elements.
The researchers considered the mass of the objects in question, their rotation, and other parameters, including an estimate of their frequency in the history of the Universe. They drew on observations from gravitational and other observatories. Their models and calculations showed that neutron star collisions produce two to a hundred times more heavy elements than neutron star-black hole collisions.
Source and credit: https://news.mit.edu/2021/neutron-star-collisions-goldmine-heavy-elements-1025, featured image: National Science Foundation, LIGO, Sonoma State University, A. Simonnet, CC0.