SIMBAD references

Supernovae (SNe) drive multiphase galactic outflows, impacting galaxy formation; however, cosmological simulations mostly use ad hoc feedback models for outflows, making outflow-related predictions from first principles problematic. Recent small-box simulations resolve individual SNe remnants in the interstellar medium (ISM), naturally driving outflows and permitting a determination of the wind loading factors of energy η_E, mass η_m, and metals η_Z. In this Letter, we compile small-box results, and find consensus that the hot outflows are much more powerful than the cool outflows: (i) hot outflows generally dominate the energy flux, and (ii) their specific energy e_s,h is 10-1000 times higher than cool outflows. Moreover, the properties of hot outflows are remarkably simple: e_s,h∝η_E,h/η_m,h is almost invariant over four orders of magnitude of star formation surface density. Also, we find tentatively that η_E,h/η_Z,h∼0.5. If corroborated by more simulation data, these correlations reduce the three hot phase loading factors into one. Finally, this one parameter is closely related to whether the ISM has a "breakout" condition. The narrow range of e_s,h indicates that hot outflows cannot escape dark matter halos with log M_halo [M_☉]≳12. This mass is also where the galaxy mass-metallicity relation reaches its plateau, implying a deep connection between hot outflows and galaxy formation. We argue that hot outflows should be included explicitly in cosmological simulations and (semi-)analytic modeling of galaxy formation.