Grand Challenge: Dynamo action in supernova-driven interstellar flows

29.03.2011

Maarit Mantere et al. are launching their Grand Challenge project entitled "Dynamo action in supernova-driven interstellar flows".

Magnetism is a universal phenomenon - the Sun, stars, planets, and galaxies all exhibit dynamically significant magnetic fields. It is generally believed that these magnetic fields are generated by a turbulent dynamo: non-uniform rotation of the cosmic object combined with the collective inductive effect of turbulent motions, are together capable of sustaining the magnetic field against diffusion. In galaxies    supernova explosions that create expanding shock fronts are the most powerful sources of interstellar turbulence.

Turbulence models of this kind are challenging in their own right, but in this application the researchers propose to extend the challenge a step further; namely, to model the galactic dynamo mechanism within such a flow. To model the galactic dynamo mechanism, numerical schemes are required capable of handling highly supersonic flows and multiscale phenomena. The researchers have developed such a model, working on scales of interest large enough for the galactic dynamo, but small enough to model the essential properties of supernova-generated turbulence. The most significant challenge is related to the vastly different time scales: the dynamo mechanism needs Gigayears to saturate, while the follow-up of the expansion of a single supernova-event needs time step of the order of 100 years.

The researchers will use two million processor hours of CSC's computing resource and four terabytes disk space. Grand Challenge projects are aimed at high-impact scientific research that requires computational or data resources exceeding CSC's standard project quotas or level of services. CSC allocates a support group for each GC project, and the GC calls are arranged twice a year.

The researchers are:

Maarit Mantere, PH.D, University on Helsinki
Frederick Gent, Ph.D. student, University of Newcastle
Andrew Fletcher, Ph.D., lecturer, University of Newcastle
Graeme Sarson, Ph.D., lecturer, University of Newcastle
Anvar Shukurov, Ph.D., professor, University of Newcastle
Ilkka Tuominen, Ph.D., professor emeritus, University of Helsinki

CSC - IT Center for Science Ltd. is a non-profit limited company administered by the Ministry of Education, Science and Culture. Having core competences in modeling, computing and information services, CSC provides versatile IT services, support and resources for academia, research institutes, and companies. The Funet communication links provide research workers with Finland's widest selection of scientific software and databases and Finland's most powerful supercomputing environment.