The Prevalence of Turbulence-Regulated Multiphase Galactic Winds in Star-Forming Galaxies

TL;DR

This study uses advanced radiative transfer modeling to show that turbulence plays a dominant role in the energy and dynamics of galactic winds, linking stellar feedback to the circumgalactic medium's structure.

Contribution

It introduces a self-consistent framework to quantify turbulence in galactic winds and demonstrates its significance in energy budgets and scaling relations.

Findings

Turbulent velocities often exceed bulk outflow speeds.

Turbulent pressure dominates over microscopic and ram pressures.

Wind energy correlates tightly with star formation energy injection.

Abstract

We build upon our previously developed multi-ion radiative transfer (RT) framework, PEACOCK, to investigate the kinematic and energetic structure of cool-to-warm galactic winds in a sample of 50 nearby star-forming galaxies. Using self-consistent constraints derived from joint modeling of Ly-alpha and multiple ultraviolet metal lines, we analyze how bulk outflows and turbulent motions contribute to the dynamics and energy budget of galactic winds in the circumgalactic medium (CGM). We find that macroscopic turbulent velocities are often comparable to, and sometimes exceed, the coherent bulk outflow velocity. The associated turbulent pressure frequently dominates over both microscopic pressure and ram pressure, indicating that turbulence is a major contributor to the kinetic energy budget of the CGM wind. Wind kinematics, ionic column densities, and metal mass outflow rates all scale systematically with stellar mass and star formation rate, demonstrating a strong coupling between stellar feedback and CGM structure. Including turbulent motions strengthens these 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, implying that stellar feedback provides sufficient power to sustain both coherent outflows and turbulence. Comparisons with phenomenological line-profile fitting methods further show that simplified treatments can introduce systematic biases in inferred wind properties. 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.