The Ionization Conditions in the Milky Way Halo: Infalling Gas toward the North Galactic Pole

Abstract

The observations of gas in the Milky Way are reviewed with an eye toward the theoretical predictions of the Galactic Fountain model for the production of halo gas. Data are shown which indicate significant variations in the ionization conditions in infalling halo gas in the northern galactic hemisphere. Besides being interesting in its own right, understanding the nature of Miky Way halo gas plays a critical role in interpreting QSO absorption lines in the study of galaxies at high redshift. (SECTION: The First Hubble Fellows Symposium)