This contribution discusses the challenges of implementing star formation and
stellar feedback processes in galaxy simulations. Insufficient
computational power and numerous poorly understood physical processes, force
simulations to adopt sub-grid models of the interstellar medium. These may
crucially bias results. We advocate for smaller (~ kiloparsec) scale
simulations of the interstellar medium to guide the development of sub-grid
models in larger simulations.
In this vein, I show results on ever increasing scales ranging from
~1 h-1 kpc3 ISM simulations, to a 1 h-1 Mpc3
simulation of a galaxy forming at high redshift, to a larger cosmological
volume, 6.25 h-1 Mpc3, evolved down to redshift 3.
We find that galactic winds can be powered
by SN implemented as point explosions in high redshift galaxies
simulated with sufficient spatial resolution.
Galaxies at lower redshift require alternative sub-grid feedback models
and we present one possible solution to generate winds from galaxies at
redshift ~4.