Princeton Center for Heliophysics Seminar

Magnetic dynamos are a ubiquitous way of growing, maintaining and structuring magnetic fields across many scales in the Universe. Turbulent, or small-scale dynamos, which power the turbulent components of the magnetic field, provide the reservoir of magnetic energy for large-scale dynamos, which, for example, build coherent fields in accretion discs, via the electromotive force, and hence are an important component of the dynamo ecosystem. Turbulent dynamos have been largely studied both theoretically and numerically in the incompressible regime, which has only limited application in both the interstellar medium and accretion discs, where there can be strong gas density fluctuations and velocity divergence. In this talk I will highlight some of our latest results in compressible (and supersonic) turbulent dynamo calculations and theory, highlighting both the similarities and differences that the supersonic turbulent dynamo has with the incompressible dynamo. Time permitting, I will also talk about our latest calculations on the compressible Kelvin Helmholtz instability dynamo, with applications for growing magnetic fields in binary neutron star mergers.