| Popis: |
The ionization of the Galactic halo is revealed by its Hα and X-ray emission and by UV absorption lines of highly ionized species (e.g. C IV, O VI). A fundamental problem for the understanding of the halo is the nature of the energy sources that ionize the warm gas and create the hot gas. Most of the energy sources in the Galaxy, e.g. hot stars and supernova remnants, are primarily confined to a relatively thin disk (∼several hundred pc) in contrast to the thick (∼ 1—several kpc) distribution of the gas. The problem with these disk sources is the transport of the energy from the disk to the halo. There is currently no model for an energy source local to the halo that is clearly capable of supplying the energy needed to maintain the observed ionization. |
