E. Battaner et E. Florido, A 2-DIMENSIONAL MODEL OF MAGNETOHYDRODYNAMICALLY DRIVEN ROTATION OF SPIRAL GALAXIES WITHOUT DARK-MATTER, Monthly Notices of the Royal Astronomical Society, 277(3), 1995, pp. 1129-1133
A steady-state two-dimensional model of the outermost region of a spir
al galaxy is presented. The magnetic field, which is able to explain t
he flat rotation curve, is calculated, without the existence of any ki
nd of dark matter. The vertical and radial distributions of the densit
y are calculated, as well as the radial and vertical velocities. The m
agnetic field strength is noticeably constant in the peripheral disc,
at about 7x10(-7) gauss, much more moderate than that obtained in our
previous model (Battaner et al.). The vertical velocities are driven b
y Parker's instabilities and induce a moderate escape of gas of about
0.1 M. yr(-1) which prevents excessive flaring.