Working as part of the ARC Centre of Excellence for All-Sky Astrophysics (CAASTRO), scientists from The Australian National University (ANU) are learning about the formation of a certain type of supernova by modelling its explosions on Raijin.
Type Ia supernovae remain a mystery to astrophysics researchers. Dr Ivo Seitenzahl says, "The details of what kind of stellar systems give rise to these supernovae are still unknown." Researchers do know that white dwarf stars are involved, but the details of how they come together to form Type Ia supernovae remain a mystery.
The research team, made up of scientists from ANU as well as Queen's University Belfast, is using theory to simulate what this supernova formation might be like. "We take a theoretically proposed model and follow the dynamics of the thermonuclear explosion. In three dimensions we need a supercomputer," says Dr Seitenzahl. "NCI supplies us with the computational resources, storage, and a very reliable architecture to let us perform the calculations needed for our research."
Based on the models, they can predict the quantities and locations of hundreds of chemical elements produced in the supernova explosion, as well as other observables such as light curves and gravitational waves. Dr Seitenzahl explains, "We then aim to compare the predictions of our model with observations of real supernovae. In doing so we make progress in our quest to find the elusive progenitors of Type Ia supernovae."
The models looking at the light coming from supernovae explosions are the hardest to run on regular computers. "The three-dimensional calculations that compute the light escaping from our explosion models are even more computationally demanding, as we need to follow 200 million particles to adequately sample all relevant interactions and obtain sufficient signal for all directions," says Dr Seitenzahl.
The findings of this modelling are challenging some previous ideas about how these supernovae are formed. They are also suggesting new ways that supernovae in neighbouring galaxies could be measured in the future, for example by using gravitational wave observatories in space.