NWU researchers are granted large-scale supercomputer time
Two researchers on shocks in Active Galaxies from the Centre for Space Research at the North-West University (NWU) have been granted 50 million processing hours on a supercomputer at the Gauss Supercomputer Centre in Germany.
Prof Felix Spanier and Dr Patrick Kilian from the NWU and their German partners, Prof Reinhard Schlickeiser and Dr Anne Stockem from the Ruhr-Universität Bochum, applied for their
Prof Felix Spanier.
Prof Patrick Kilian.
supercomputer project to study jets in Active Galactic Nuclei (AGN).
Spanier said this substantial amount of computing time can be related to 1 426 years’ of work on a typical modern office PC. The Gauss Supercomputer Centre is a European initiative, where some of the world’s fastest supercomputing centres have joined forces. It is number 23 on the list of the world’s fastest supercomputers.
“Competition for these resources is very fierce. We had to give really good reasons why we should be granted computing time,” Spanier said. “The computing resources one needs for this project go beyond what any university can deliver. This amount of computing time would cost R25 million on the free market.”
Spanier and Kilian have a long track record of successful supercomputing projects around the globe. “By now we spend more than 10 million Central Processing Unit (CPU) hours per year”, Kilian explained.
According to Spanier AGN’s are cores in distant galaxies, with an energy output higher than a complete galaxy. “They are very interesting objects since they can be observed despite their distance at very high energies.
“The energy an AGN emit is typically bundled in a jet emitted from a black hole. This jet shows ‘blobs’ (large plasma chunks and ‘knots’ (density enhancements in the jet).
“The question now at hand is, what happens when these blobs collide with each other?”
He said studying this question is in fact much more complicated than it seems at first glance, since these jets have basically nothing in common with physics people know from their daily experience. “They consist of an incredibly thin, completely ionized gas, kept in shape by magnetic fields. This gas, called plasma, is not only extremely hot, but also contains particles with energies beyond our imagination.”
Spanier said their team now uses the Particle-in-Cell method to simulate these jets. Charged particles are simulated, which produce electric and magnetic fields, and these in turn act on the particles. “This approach is very useful for computer simulations, because it can be easily implemented and is quite well understood.”
Spanier and Kilian have been working on this method for almost a decade.