The Dynamical State of the Interstellar Gas and Field. V. Reduced Dynamical Equations
Abstract
The dynamical equations for a gas suspended on a horizontal magnetic field are simplified and re duced by supposing that the Alfvén speed is large compared with the thermal velocity and that the scales are small compared with the scale height. The simplification renders the equations tractable in more complicated physical situations than the complete set of hydromagnetic equations used in some of the earlier investigations. A number of results for hydrostatic equilibrium, and for small perturbations of an equilibrium, are worked out to illustrate the properties of the approximate system of equations. Com parison with the special cases treated from the complete equations indicates that most of the essential features of the dynamics appear to be retained by the simplified equations. The simplified equations are to be applied to more complicated cases in future papers
 Publication:

The Astrophysical Journal
 Pub Date:
 October 1968
 DOI:
 10.1086/149740
 Bibcode:
 1968ApJ...154...57P