The Effects of Cosmic-Ray Diffusion and Radiative Cooling on the Galactic Wind from the Milky Way

Abstract

The effects of cosmic-ray diffusion and radiative cooling on the structure of the Galactic wind are studied using a steady state approximation. It is known that realistic cooling processes suppress the wind from launching. The effects of cosmic-ray diffusion are also supposed to be unfavorable for launching the wind. Both of these effects have not been studied simultaneously in a steady-state approximation of the wind. We find 327,254 solutions of the steady-state Galactic wind and confirm that: the effect of cosmic-ray pressure depends on the Alfv{é}n Mach number, the mass flux carried by the wind does not depend on the cosmic-ray pressure directly (but depends on the thermal pressure), and the typical conditions found in the Galaxy may correspond to the wind solution that provides metal polluted matters at a height of $\sim 300$~kpc from the disk.

18 pages, 13 figures, accepted for publication in ApJ