How do stars form? In clouds of gas millions of kilometres across, over millions of years, how do stars form? We know that gravity and electromagnetism and chemistry, pulling together vast clouds of gas, eventually lead to the burning balls of Hydrogen and Helium that we can see in the night sky. But in the turbulent clouds of gas, what is taking place? Researcher James Beattie, a PhD student from The Australian National University’s Research School of Astronomy and Astrophysics, is using the fundamental rules of the Universe that govern the flow of air and water on Earth to describe the flows of gas taking place in star-forming clouds across the universe.
Fluid flow is a famously difficult mathematical problem to solve. For simple situations, the standard equations can be easily calculated, but when they become more complex, a supercomputer is needed. That’s where NCI steps in. By harnessing the computing power of thousands of processors working in parallel, Mr Beattie simulates the incredible three-dimensional structures that form in the gas as it coalesces into stars: long thin strands, striations and shockwaves all twirling together. To get the most accurate results from the theoretical calculations, Mr Beattie includes as many variables as possible, including magnetic fields, turbulence, thermodynamics and more. Once the results from the simulations come through, they are analysed using statistical methods and compared to telescope observations, giving further insights and sharpening our knowledge of exactly how swirling clouds of gas end up producing stars.
“It’s only with the resources at NCI that we can create really high-resolution simulations that properly represent these structures.”
As our knowledge increases, so does our ambition. The next steps for simulating star formation involve increasing the resolution and scale of the modelling to cover a wider area with more detailed results. Of course, that level of detail requires even more computing power, computing power which arrived in November 2019 in the form of NCI’s new Gadi supercomputer. With the final Gadi computer coming in at around 6 times the computational performance of its predecessor, the research of the Australian astrophysics community stands in good stead in coming years.
To read more about this work, the paper Filaments and striations: anisotropies in observed, supersonic, highly-magnetised turbulent clouds is now available.