Numerical Modeling of Galactic Superwinds with Time-evolving Stellar Feedback

TL;DR

This paper uses hydrodynamic simulations to study galactic superwinds driven by evolving stellar feedback, focusing on radiative cooling effects, bubble formation, and emission line predictions in starburst regions.

Contribution

It introduces a time-dependent superwind model incorporating radiative efficiency and ionization states, advancing understanding of wind structures and emission in star-forming galaxies.

Findings

Radiative cooling superwinds depend on specific parameter regimes.

Non-equilibrium ionization significantly affects emission line profiles.

Wind thermal feedback causes deviations from collisional ionization over time.

Abstract

Mass-loss and radiation feedback from evolving massive stars produce galactic-scale superwinds, sometimes surrounded by pressure-driven bubbles. Using the time-dependent stellar population typically seen in star-forming regions, we conduct hydrodynamic simulations of a starburst-driven superwind model coupled with radiative efficiency rates to investigate the formation of radiative cooling superwinds and bubbles. Our numerical simulations depict the parameter space where radiative cooling superwinds with or without bubbles occur. Moreover, we employ the physical properties and time-dependent ionization states to predict emission line profiles under the assumption of collisional ionization and non-equilibrium ionization caused by wind thermal feedback in addition to photoionization created by the radiation background. We see the dependence of non-equilibrium ionization structures on the time-evolving ionizing source, leading to a deviation from collisional ionization in radiative cooling wind regions over time.