2009/01/04 by Christophe Gissinger, Sebastien Fromang, Emmanuel Dormy · 3 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Fluid dynamics and aerodynamics studies #Geomagnetism and Paleomagnetism Studies #Solar and Space Plasma Dynamics #astro-ph.GA
paper · pdf · doi:10.1111/j.1745-3933.2009.00616.x
5 pages, 6 figures
arxiv created 2009/01/04 · openalex publication_date 2009/02/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Abstract We present kinematic simulations of a galactic dynamo model based on the large-scale differential rotation and the small-scale helical fluctuations due to supernova explosions. We report for the first time direct numerical simulations of the full galactic dynamo using an unparametrized global approach. We argue that the scale of helicity injection is large enough to be directly resolved rather than parametrized. While the actual superbubble characteristics can only be approached, we show that numerical simulations yield magnetic structures which are close to both the observations and the previous parametrized mean field models. In particular, the quadrupolar symmetry and the spiraling properties of the field are reproduced. Moreover, our simulations show that the presence of a vertical inflow plays an essential role to increase the magnetic growth rate. This observation could indicate an important role of the downward flow (possibly linked with galactic fountains) in sustaining galactic magnetic fields.