[Previous] | [Session 52] | [Next]
M.-M. Mac Low (Amer. Mus. Nat. Hist.)
The impact of supernova-driven galactic winds on the formation and evolution of galaxies depends on how well the high-velocity gas in the wind can couple to the rest of the gas in the galaxy and its halo. Numerical simulations demonstrate that this coupling will generally be rather poor, as the wind tends to follow the shortest path to vacuum. As a result, winds will generally not carry off great amounts of mass from a galaxy, but may carry substantial amounts of kinetic energy and metals generated in the supernova explosions driving them. Many approximations for star formation in cosmological simulations have trouble reproducing this result due to excessive numerical diffusion and cooling. The simulations also suggest that observations of galactic winds tend to show only the densest parts, and so must be interpreted cautiously.
M-MML is partially supported by an NSF CAREER grant, number AST99-85392.