Magnetic field saturation in simulations of the supernova-driven ISM

by Dr Oliver Gressel (Nordita)

Wednesday 5 Dec 2012, 13:30 → 14:15 Europe/Stockholm

122:026

The emergence of large-scale magnetic fields observed in the diffuse interstellar medium is explained by a mean-field dynamo. We diagnose turbulent transport coefficients by means of the test-field method. For the first time, we also derive quenching functions for the dynamo α-effect, diamagnetic pumping, and turbulent diffusivity, which are compared with theoretical expectations. For near-equipartition strength fields, we observe the suppression of the vertical wind. Because this potentially affects the removal of small-scale magnetic helicity, new concerns may arise about circumventing constraints imposed by the conservation of magnetic helicity at high magnetic Reynolds numbers.

arXiv