Karl-Heinz Rädler Awarded the Schwarzschild Medal 2013

by Axel Brandenburg 31 Dec 2013 Awards
Published in the "From the Institute" section of Nordita News issue 4, 2013

During their meeting on November 19th, members of the Astrophysics Group celebrated the award of this years Schwarzschild Medal to Karl-Heinz Rädler from the Leibniz-Institute for Astrophysics in Potsdam who is one of Nordita's frequent visitors. This medal is awarded annually by the German Astronomical Society to astronomers of highest scientific standing.

Karl-Heinz is one of the fathers of modern mean-field dynamo theory. In seminal papers between 1966 and 1969, he identified several effects that characterize the evolution of large-scale magnetic fields in cosmic bodies such as the Sun and other stars, planets, and even galaxies.

During the 1970s, he developed numerical approaches to compute global nonaxisymmetric mean-field models. Toward the end of the 1980s, he was allowed to travel from East Germany to the West and spent extended periods also in Helsinki, where he computed numerically the first nonlinear, nonaxisymmetric dynamo solutions that were relevant for explaining the magnetic fields in rapidly rotating stars. During the 1990s, acting as the founding director of the Astrophysical Institute Potsdam (now the Leibniz-Institute) he participated in preparatory calculations for the Karlsruhe dynamo experiment that demonstrated self-excited magnetic fields in helically flowing liquid sodium. In recent years, he developed a method for computing numerically turbulent transport coefficients from simulations. Much of his work has been instrumental for recent developments in the astrophysics group at Nordita.

During his last visit he computed analytic solutions to certain spatially periodic flow patterns called Roberts flows that we now understand as producing highly unconventional types of large-scale dynamos. In the picture, he explains striking properties of such flows that will be part of a new paper he is currently writing with members of the group at Nordita.

Members and visitors of the Nordita Astrophysics group, left to right: Bidya Binay Karak, Ebru Devlen, Anthony van Eysden, Sarah Jabbari, Nishant Singh, Matthias Rheinhardt, Illa R. Losada, Mikhail Modestov, Karl-Heinz Rädler, Elizabeth Cole, Dhruba Mitra, Lars Mattsson, Mikhail Liberman, and behind the camera Axel Brandenburg.