Stars, Planets, and ISM Seminar

Kinematically Coherent, Turbulence-Regulated Galactic Winds: New Constraints from RT Modeling of Lyα and UV Metal Lines

Galactic winds driven by stellar feedback play a central role in regulating galaxy evolution, yet their physical structure and energetics remain incompletely understood. In this talk, I will present new constraints on the kinematics and energy budget of cool–to–warm galactic winds in the circumgalactic medium (CGM) based on joint modeling of Lyα and multiple ultraviolet metal lines in 50 nearby star-forming galaxies observed with HST/COS. Using PEACOCK, a three-dimensional Monte Carlo radiative transfer framework for multiphase outflows, we find that macroscopic turbulent velocities frequently exceed the bulk outflow velocity, indicating that turbulence is a necessary component of wind kinematics. The inferred kinematics show strong coherence among low- and high-ionization metal lines in both bulk and turbulent velocities, consistent with a dynamically coupled multiphase wind, while neutral hydrogen shows weaker correspondence with metals, suggesting incomplete mixing and a distinct kinematic structure. Including turbulence further strengthens CGM–galaxy scaling relations and favors an energy-driven feedback regime: the total kinetic energy flux of the cool–to–warm CGM correlates tightly with the mechanical energy injection rate from star formation. Taken together, these results support a turbulence-regulated picture of galactic winds, in which a substantial fraction of feedback energy is stored in turbulent motions within a multiphase CGM.