# Global Simulations of Galactic Discs: Violent Feedback from Clustered Supernovae during Bursts of Star Formation

## TL;DR

This paper uses high-resolution simulations to show that clustered supernovae in gravitationally unstable galactic discs produce violent winds and a turbulent, restructured disc, highlighting the importance of feedback variability in galaxy evolution.

## Contribution

It introduces a novel simulation approach that captures the effects of clustered supernova feedback on galactic disc dynamics and wind generation.

## Key findings

- Violent winds with high mass loading factors are driven by clustered supernovae.
- Self-gravity is essential for producing these violent winds.
- Galactic winds and disc turbulence are highly variable over short timescales.

## Abstract

A suite of idealised, global, gravitationally unstable, star-forming galactic disc simulations with 2 pc spatial resolution, performed with the adaptive mesh refinement code {\sc ramses} is used in this paper to predict the emergent effects of supernova feedback. The simulations include a simplified prescriptions for formation of single stellar populations of mass $\sim 100 \, M_{\odot}$, radiative cooling, photoelectric heating, an external gravitational potential for a dark matter halo and an old stellar disc, self-gravity, and a novel implementation of supernova feedback. The results of these simulations show that gravitationally unstable discs can generate violent supersonic winds with mass loading factors $\eta \gtrsim 10$, followed by a galactic fountain phase. These violent winds are generated by highly clustered supernovae exploding in dense environments created by gravitational instability, and they are not produced in simulation without self-gravity. The violent winds significantly perturb the vertical structure of the disc, which is later re-established during the galactic fountain phase. Gas resettles into a quasi-steady, highly turbulent disc with volume-weighted velocity dispersion $\sigma > 50 \, {\rm km/s}$. The new configuration drives weaker galactic winds with mass loading factor $\eta \leq 0.1$. The whole cycle takes place in $\leq 10$ dynamical times. Such high time variability needs to be taken into account when interpreting observations of galactic winds from starburst and post-starburst galaxies.