Supernova secrets decoded via supercomputers

Using supercomputers, scientists develop Accuracy Supernova simulations move from one-dimensional to detailed three-dimensional models.

Supernovae – massive exploding stars – are some of the most spectacular events in the universe. They are very complex. To understand what causes them, researchers Princeton University Users simulate these explosions on supercomputers at the Department of Energy’s Argonne Leadership Computing Facility facility. The research also gives us insight into how these explosions formed many of the elements in our universe.

Scope and Challenges of the Research

The primary objective of these researchers is to decode the processes unfolding inside these stars. This knowledge will allow us to predict which stars will explode. It will also help determine which will form neutron stars and black holes. These processes cover many complex topics, including neutrino physics and nuclear physics.

This visualization shows the results of a state-of-the-art 3D simulation of a supernova explosion and neutron star birth. It is a rare event that the entire stellar evolution of such an object, including the physics of convection and radiation, has been simulated in 3D. The image shows the deep core shrinking after the explosion due to neutrino cooling and depletonization to become a cooler, smaller neutron star. Credit: ALCF Visualization and Data Analysis Team; Adam Burroughs and the Princeton Supernova Theory Group, Princeton University

Scientists have been studying this topic for 60 years, but computers have not been able to provide accurate simulations. Previous models could only simulate explosions in one dimension. These model explosions do not reflect how they happened in real life. Clearly, something is missing. The scientists discovered that in the one-dimensional simulations, the internal structures of the stars were missing. They also don’t see the instabilities in those structures. Structures and instabilities change depending on how stars form, their rotation, and the heavier elements they contain.

The power of three-dimensional simulations

To bridge this knowledge gap, scientists realized they needed to model supernovae in three dimensions in space. They should also include how the explosion changed over time and changed in speed. Even modeling half-a-second before the explosion, the simulation was even more complicated. Moving from one dimension to three dimensions increased the complexity by a factor of 10,000!

To access that kind of computing power, the researchers turned to the DOE Office of Science. They got time on ALCF’s supercomputers to run their models.

With current 3D simulations, model supernovae now behave the way supernovae behave in nature. This model is closer than ever to describing and predicting what happens in these eruptions. Scientists are also working to extend the length of their simulations. They aim to cover four to five seconds per event.

Conclusion

As scientists improve their simulations with the help of DOE’s supercomputers, they will better understand what happens in these stars’ final moments.