The Westerbork SINGS survey. III. Global magnetic field topology

The authors model the WRST results for a dozen galaxies from the Spitzer Infrared Nearby Galaxy Survey based on Braun et al. 2007 (A&A, 461, 455). Using sensitive Faraday rotation study they find that the general magnetic field topology for the thick-disk emission zone is an axisymmetric spiral with a quadrupole dependence on height above the mid-plane in all cases. They also propose an axisymmetric spiral field in the galaxy mid-plane. The field topology in the upper halo of galaxies is a mixture of two distinct types: a simple extension of the axisymmetric spiral quadrupole field of the thick disk and a radially directed dipole field.