SMuK 2021 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 10: Astrophysics II
EP 10.1: Vortrag
Freitag, 3. September 2021, 14:00–14:15, H5
Structure formation in isothermal supersonic plasmas: magnetic helicity inverse transfer — •Jean-Mathieu Teissier1 and Wolf-Christian Müller1,2 — 1Technische Universität Berlin, Berlin, Deutschland — 2Max-Planck/Princeton Center for Plasma Physics, Princeton, NJ, USA
The interstellar medium exhibits large-scale magnetic structures and a wide range of turbulent sonic Mach numbers (from subsonic to Mach numbers of order 10 and beyond), with different turbulent drivers. A mechanism to explain the presence of large-scale structures is the inverse transfer of magnetic helicity, a quadratic ideal invariant describing some topological aspects of the magnetic field. Its inverse transfer has been investigated in direct numerical simulations (DNS), up to this work, only in incompressible and low Mach number cases. We present results from DNS in the isothermal case with Mach numbers ranging up to about 10 with different turbulence drivers and point out differences and similarities with the incompressible case, in particular with respect to spectral scaling laws and Fourier shell-to-shell transfers.
Our work suggests that some incompressible dynamical balances are extended in the supersonic regime and that the driving type affects the dynamics more significantly than the turbulent Mach number alone.