Exploring heavy element creation in neutron-star mergers

Violent collisions of neutron stars are believed to be the origin of, for example, gold and platinum. Now, subatomic physicists at Chalmers will explore how such heavy elements are formed. In a new project, granted SEK 29.6 million in funding from the Knut and Alice Wallenberg Foundation, they will perform novel experiments to understand how the laws of subatomic physics influence the collision of neutron stars.

“Recent breakthroughs in astronomical observations, especially the detection of gravitational waves, together with advances in instrumentation for subatomic physics experiments offer unique research opportunities. We will be able to understand how nuclear fission impacts the creation of heavy elements in the collision of neutron stars.
I am thrilled to be a part of this endeavor and grateful to the Knut and Alice Wallenberg Foundation for making this research possible,” says Andreas Heinz, Associate Professor at the Department of Physics at Chalmers.

Together with Doctor Håkan T. Johansson and Professor Thomas Nilsson, he will investigate how the laws of the subatomic world, and in particular nuclear fission, influence the creation of heavy elements in the universe. For five years, the Chalmers researchers will carry out innovative experiments at the European research facility CERN in Switzerland.

“To understand how heavy elements are formed, astronomical observations alone are not sufficient. It is also necessary to understand the underlying nuclear physics processes caused by a high flux of neutrons,” says Andreas Heinz, leader of the recently founded project.

In total, the Knut and Alice Wallenberg Foundation has granted SEK 541 million to 18 outstanding basic research projects in medicine, science and technology that are considered to have the possibility to lead to future scientific breakthroughs.

Out of the 18 projects, three will be conducted at Chalmers. At the Department of Physics, Professor Mikael Käll will lead a project on light sources of the future. At the Department of Space, Earth and Environment, Professor Kirsten Kraiberg Knudsen will lead a project on the origin and fate of dust in the universe.

Text: Mia Halleröd Palmgren

Portrait photo: Anna-Lena Lundqvist

More about the project and the financier

The research project "Creation of heavy elements in neutron-star mergers" has been granted SEK 29,600,000 for five years by the Knut and Alice Wallenberg Foundation.

The project is led by Andreas Heinz, Associate Professor at the Department of Physics at Chalmers. Professor Thomas Nilsson and Doctor Håkan T. Johansson, both from the same department, are also participating in the project. The Knut and Alice Wallenberg Foundation is Sweden's largest private research funder and one of the largest in Europe.

What is a neutron star?

A neutron star is the remaining core of a star, which had about 10-20 times the mass of the sun. The core of such a star collapses once it runs out of material for nuclear fusion. Infalling matter bounces back from the extremely dense core, leading to a supernova explosion. The remaining core forms a neutron star with a density as high, or higher, than that of an atomic nucleus – with masses similar to those of the sun within a sphere of a few kilometers in diameter. The exact composition of neutron stars is not known. They are, short of black holes, the densest known objects in the universe.

Published: Wed 30 Sep 2020.