Galaxies are made up of billions upon billions of particles. Understanding how a particle interacts with its environment is a tricky process, understanding how something as elusive as a Dark Matter particle behaves is even trickier. But that is what Dr Iwanus and other national collaborators have done on an enormous scale, in their latest research published in The Monthly Notices of the Royal Astronomical Society.
To try and make sense of the problem Iwanus had to model the complex interactions between 134,217,728 particles, which essentially are set in motion and then just evolve under the laws of physics that we currently understand. Iwanus then makes slight perturbations to see what matches up with the reality we know compared with what happens in the simulations. For this work, they used the Artemis HPC at the University of Sydney.
The supercomputer allows you to run the simulation thousands of times, each time slightly adjusting the parameters and seeing how well that resembles reality. This “reality” is the actual observations we make using huge telescopes arrays spread all over the world (and also in space!).
Get a copy of the paper here: https://arxiv.org/pdf/1902.02437.pdf