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Paper: Galactic Superwinds at Low and High Redshift
Volume: 240, Gas and Galaxy Evolution: A Conference in Honor of the 20th Anniversary of the VLA
Page: 345
Authors: Heckman, T. M.
Abstract: In this contribution I summarize our current knowledge of the nature and significance of starburst-driven galactic superwinds. These flows are driven primarily by the kinetic energy supplied by supernovae. Superwinds are complex, multiphase phenomena requiring a panchromatic observational approach. They are ubiquitous in galaxies in which the global star-formation rate per unit area exceeds roughly 10-1 Msolar yr-1 kpc-2 (a condition satisfied by local starbursts and high-redshift Lyman break galaxies). Data on X-ray emission, optical line-emission, and optical/UV interstellar absorption lines together imply that the mass outflow rates are comparable to the star-formation rates and that the conversion of kinetic energy from supernovae to superwind is quite efficient (~30 to 100%). Measured/inferred outflow speeds range from a few × 102 to 103 km s-1 and appear to be independent of the rotation speed of the ``host'' galaxy. The outflows are dusty (dust/gas ratios of ~1% by mass). These properties imply that superwinds may have established the mass-metallicity relation in elliptical and bulges, polluted the intergalactic medium to a metallicity of ~10 to 30% solar, heated the intergalactic medium by up to ~1 kev per baryon, and ejected enough dust into the intergalactic medium to have potentially observable consequences.
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