Frederick A. Gent

The distribution of mean and fluctuating magnetic fields in the multiphase interstellar medium

We explore the effects of the multi-phase structure of the interstellar medium (ISM) on galactic magnetic fields. Basing our analysis on compressible magnetohydrodynamic (MHD) simulations of supernova-driven turbulence in the ISM, we investigate the properties of both the mean and fluctuating components of the magnetic field. We find that the mean magnetic field preferentially resides in the warm phase and is generally absent from the hot phase. The fluctuating magnetic field does not show such pronounced sensitivity to the multi-phase structure.

Supernova-regulated ISM. V. Space and Time Correlations

We apply correlation analysis to random fields in numerical simulations of the supernova-driven interstellar medium (ISM) with the magnetic field produced by dynamo action. We solve the thermo-magnetohydrodynamic (MHD) equations in a shearing, Cartesian box representing a local region of the ISM, subject to thermal and kinetic energy injection by supernova explosions, and parameterized optically-thin radiative cooling. We consider the cold, warm\, and hot phases of the ISM separately; the analysis mostly considers the warm gas, which occupies the bulk of the domain. Various physical variables have different correlation lengths in the warm phase:

The supernova-regulated ISM: III. Generation of vorticity, helicity, and mean flows

40 pc

Magnetic Shocks and Substructures Excited by Torsional Alfvén Wave Interactions in Merging Expanding Flux Tubes

,

Long-term variations of turbulent transport coefficients in a solarlike convective dynamo simulation

50 pc

The supernova-regulated ISM : IV. A comparison of simulated polarization with Planck observations

, and

Supernovae driven turbulence in the interstellar medium

60 pc

Space- and time-correlations in the supernova driven interstellar medium

for random magnetic field, density, and velocity, respectively, in the midplane. The correlation time of the random velocity is comparable to the eddy turnover time, about

Sensitivity to luminosity, centrifugal force, and boundary conditions in spherical shell convection.

10^7 yr

Pencil-Code special edition: modelling supernova driven turbulence

, although it may be shorter in regions with higher star formation rate. The random magnetic field is anisotropic, with the standard deviations of its components