A model of supernova feedback in galaxy formation

摘要: ABSTRA C T A model of supernova feedback during disc galaxy formation is developed. The incorporates infall cooling gas from a halo, and outflow hot multiphase interstellar medium (ISM). star rate determined by balancing the energy dissipated in collisions between cold clouds with that supplied supernovae marginally unstable to axisymmetric instabilities. Hot created thermal evaporation remnants, criteria are derived estimate characteristic temperature density component hence net mass rate. number refinements investigated, including simple galactic fountain, response pressure gas, pressure-induced chemical evolution. main conclusion this paper low rates can expel large fraction dwarf galaxy. For example, circular speed ,50 km s 21 ,60‐80 per cent its over time-scale ,1 Gyr, never exceeds ,0.1 M( yr . Effective therefore take place quiescent mode does not require strong bursts formation. Even galaxy, such as Milky Way, might have lost much 20 supernova-driven wind. models developed here suggest galaxies at high redshifts will average may contain extended gaseous discs largely unprocessed gas. Such explain numbers, metallicities metallicity dispersions damped Lyman systems.