Galactic winds - How to launch galactic outflows in typical Lyman-break
  galaxies
  We perform hydrodynamical simulations of a young galactic disc embedded in a
hot gaseous halo using parameters typical for Lyman break galaxies (LBGs). We
take into account the (static) gravitational potentials due to a dark matter
halo, a stellar bulge and a disc of stars and gas. Star formation is treated by
a local Kennicutt-Schmidt law. We simplify the structure of the interstellar
medium by restricting the computational domain to a 25th of the full azimuthal
angle, effectively assuming large-scale axisymmetry and neglecting any effects
of spiral structure, and focus on the large-scale ISM drivers, the
superbubbles. Supernovae are triggered randomly and have preset event sizes of
several tens to hundreds. We further investigate different halo gas pressures
and energy injection methods. Many of our simulated galaxies, but not all,
develop bipolar outflows. We characterise the strength of the outflow by mass
and energy outflow rates, and investigate the effect of changes to the details
of the model. We find that supernovae are more effective if comprised into
larger superbubbles. The weight and the pressure of the halo gas is able to
quench galactic outflows. The wind emerges from a series of superbubbles in
regions where a critical star formation density is exceeded. The superbubbles
expand into the gaseous halo at slightly supersonic speed, producing radiative
shock waves with similar characteristics as the absorptions systems observed
around LBGs.
