Is Alfvén’s Critical Ionization Velocity Important at the Galactic Centre?

If the relative velocity between a plasma and a molecular cloud impinging on it exceeds the Alfven critical ionization velocity, then the surface of the molecular cloud can be ionized. This phenomenon has been used to model some of the ionized regions at the Galactic Centre. A review of the mechanism behind Alfven’s critical ionization phenomenon is presented here, and its use at the Galactic Centre is discussed.