The Equilibrium of an Interstellar Magnetic Disk

Equilibrium models of a cool, dense interstellar gas cloud permeated by the locally distorted galactic magnetic field are constructed using a model in which the cloud is assumed to be an infinitely thin disk of finite radius. This approximation is valid provided that the cloud is sufficiently cool. The cloud is assumed to be axisymmetric, isothermal and of mass $$10^3M_\odot$$ . The solutions show some enhancement of the magnetic field in the cloud compared to the background strength of 2 × 10 ⁻⁶ Gauss. The effects of uniform rotation about the axis of symmetry are examined. Considerably stronger magnetic fields are found in the rotating disks and in some models the field lines have snapped off forming neutral rings.