Influence of Star Formation on Large Scale Structures of Galactic Magnetic Fields

Аннотация

In order to study magnetic field generation in galaxies with active processes such as intensive star formation, supernovae explosions, etc, a model is needed to differentiate between the properties of interstellar medium in different parts of the galactic disk. In this paper we consider galactic dynamo equations with stochastic coefficients where the parameters responsible for dissipation randomly depend on time and spatial coordinates and are distributed around two values corresponding to aweakly heated neutral component and a hot ionized component. Ionized gas is assumed to be concentrated in small regions evenly distributed over the galactic disk plane. The ratio of the total area of such regions to the entire disk plane corresponds to the mean surface star-formation density in the given region of the galactic disk. Unlike in our previous papers, we take into account the dissipation in the disk plane. We have obtained numerical estimates of the exponential growth rate for different numbers of areas containing ionized gas. We show that the influence of the fluctuations on the magnetic field behavior has a threshold nature; intensive star formation leads to the destruction of large scale magnetic field structures.