Properties of Galactic Outflows: Measurements of the Feedback from Star Formation

Properties of starburst-driven outflows in dwarf galaxies are compared with those in more massive galaxies. Over a factor of ~10 in galactic rotation speed, supershells are shown to lift warm ionized gas out of the disk at rates up to several times the star formation rate. The amount of mass escaping the galactic potential, in contrast to the disk, does depend on the galactic mass. The temperature of the hottest extended X-ray emission shows little variation around ~10^6.7 K, and this gas has enough energy to escape from the galaxies with rotation speed less than approximately 130⁺²⁰_-40 km s^-1.