When Supernovae-driven Outflows Meet with the Circumgalactic Medium
Most metals do not reside in galaxies where they were born, posing the "missing metals" problem. Supernovae (SNe) launch multiphase galactic winds, which naturally drive the metals out. High-resolution simulations show that hot (T>~ 105 K) outflows carry the majority of the metals and energy. How the enriched hot outflows evolve on large scales is critical to understand the fate of the ejected metals. We implement SNe-driven outflows in galactic scale simulations, which adopt the loading efficiencies from small-box simulations. We investigate the evolution of the outflows -- whether they break into the intergalactic space, become part of the circumgalactic medium (CGM), or condense into cool phases. I will discuss how understanding these physical processes gives insight into a series of observables of the CGM: quasar absorption lines of highly ionized metals, X-ray emission and absorption, and high-velocity clouds of the Milky Way.