ASTROPHYSICS

An international research collaboration led by the University of Würzburg delved into the subjects of turbulence and particle acceleration in the solar wind by performing highly complex numerical simulations leveraging the particle-in-cell (PiC) approach, a technique used to solve a certain class of partial differential equations thus capable of studying these phenomena. In order to model the complex system of different waves, particles and electromagnetic fields self-consistently, the use of massive computing power such as provided by high performance computing system SuperMUC is inevitable.

Observations show that Earth is constantly bombarded by highly energetic particles that are called cosmic rays. A possible explanation for the origin of the cosmic rays as well as their energy distribution is particle acceleration at shock fronts. Several different physical processes take place there, but due to the large astrophysical distances it is, unfortunately, impossible to study these in-situ. One way out is large scale computer simulations.

(Type Ia supernovae, gigantic astrophysical explosions that completely disrupt one star and shine brighter than an entire galaxy consisting of 100 billion stars, have been successfully used to measure distances in the Universe. But what are the stars that give birth to Type Ia supernovae? The answer to this question remains elusive despite advances in modelling and observing these cosmic events over the past decades. From the perspective of theoretical modelling, only detailed multi-dimensional simulations of the explosion process on the most powerful supercomputers offer a way to tackle this long-standing problem.