Comments on a formation scenario of the two-component protogalaxy by galactic magnetic fields

Within the framework of the two-component protogalaxy model, the components of which are dense cold clouds and diffuse coronal gas, we discuss the sta bility condition of the dense clouds against the Kelvin-Helmholtz instabili ty (KHI). Interestingly the stability condition of the clouds against KHI d etermines the global properties of the protogalaxies. Especially, in this p aper, the effect of the magnetic field against KHI is examined. The author hypothesizes the two-component mixture to be magnetized. It is known that w hen the relative speed between two contacting fluids is smaller than the Al fven speed, it is possible for KHI to be suppressed due to the magnetic fie ld. Obviously, the efficiency of stabilization against KHI by this effect i s related to the global property of the two-component protogalaxies. Hence, we find that the two-component model of the protogalaxy is compatible with the scenario of galaxy formation via a magnetic field.