The Dynamical State of the Interstellar Gas and Field. III. Turbulence and Enhanced Diffusion

The dynamical instability of the interstellar gas, caused by the galactic cosmic rays and magnetic field, is examined for the purpose of gaining a more detailed understanding of the phenomenon. It is shown that a tissue of field, formed by superposing alternate layers of field at right angles to each other, fails to produce stability. It is shown that the instability develops very short wavelengths in the direction perpendicular to the galactic gravitational field g and magnetic field B. The result is that the interstellar gas must be in a continual state of turbulence and fragmentation down to scales of 1 pc or less, terminating only when the clouds become so dense that self-gravitation becomes dominant The turbulence and fragmentation enhance ambipolar diffusion to such an extent that the field escapes from the gas rapidly compared to the usual ambipolar rates It is suggested that this may contribute to the escape of the magnetic fields from the interstellar gas which forms stars