Hydrostatic equilibrium in a magnetized, warped Galactic disc

Hydrostatic equilibrium of the multiphase interstellar medium in the solar vicinity is reconsidered, with the regular and turbulent magnetic fields tr eated separately. The regular magnetic field strength required to support t he gas is consistent with independent estimates, provided that energy equip artition is maintained between turbulence and random magnetic fields. Our r esults indicate that a mid-plane value of B-0 = 4 muG for the regular magne tic field near the Sun leads to more attractive models than B-0 = 2 muG. Th e vertical profiles of both the regular and random magnetic fields contain disc and halo components, the parameters of which we have determined. The l ayer at 1 less than or similar to \z \ less than or similar to 4kpc can be overpressured and an outflow at a speed of about 50km s(-1) may occur there , presumably associated with a Galactic fountain flow, if B-0 = 2 muG. We show that hydrostatic equilibrium in a warped disc must produce asymmetr ic density distributions in z, in rough agreement with H I observations in the outer Galaxy. This asymmetry may be a useful diagnostic of the details of the warping mechanism in the Milky Way and other galaxies. We find indic ations that gas and magnetic field pressures are different above and below the warped midplane in the outer Galaxy, and quantify the difference in ter ms of turbulent velocity and/or magnetic field strength.