RädlerFest: Alpha Effect and Beyond

Session

Session 5

15 Feb 2011, 09:00

Wenner-Gren Center, floor 7, Hörsalen (Wenner Gren Center)

260. Galactic dynamos need galactic outflows to survive

Prof. Anvar Shukurov (School of Mathematics and Statistics, Newcastle University, U.K.)

15/02/2011, 09:00

We discuss mean-field disc dynamos (mainly as applied to galaxies) subject to magnetic helicity conservation constraint. We demonstrate how this constraint enriches the dynamo model with physical contant and facilitates detailed comparison of the theory with observations.

261. Dynamo action in thermally unstable interstellar flows

Prof. Maarit Mantere

15/02/2011, 09:30

Numerous studies have investigated the role of thermal instability in regulating the phase transition between the cold cloudy and warm diffuse medium of the interstellar medium. Considerable interest has also been devoted in investigating the properties of turbulence in thermally usntable flows, special emphasis on molecular clouds and the possibility of star formation. In this study, we...

263. A Shell Model for Turbulent Magnetic Dynamo

Dr Giuseppina Nigro

15/02/2011, 10:00

Using the magnetohydrodynamic (MHD) description, we develop a nonlinear dynamo model that couples the evolution of the large scale magnetic field with turbulent dynamics of the plasma at small scale by electromotive force (e.m.f.) in the induction equation at large scale. The nonlinear behavior of the plasma at small scale is described by using a MHD shell model for velocity field and...