# Structure distribution and turbulence in self-consistently supernova-driven ISM of multiphase magnetized galactic discs

## TL;DR

This study uses high-resolution simulations to explore how magnetic fields and supernova feedback influence the structure, star formation rate, and dynamics of the interstellar medium in galactic discs, revealing key insights into galaxy evolution.

## Contribution

It provides a detailed analysis of the effects of magnetic fields and supernova feedback on galactic disc structure and star formation, with new insights into their coupling and turbulence spectra.

## Key findings

- Supernova explosions can reproduce observed star formation rates with magnetic fields of a few μG.
- The vertical structure aligns with a simple analytical model based on energy equilibrium.
- Coupling between supernovae and gas is around 1.5%, increasing with magnetic field strength.

## Abstract

Galaxy evolution and star formation are two multi-scale problems tightly linked to each other. To understand the interstellar cycle, which triggers galaxy evolution, it is necessary to describe simultaneously the large-scale evolution widely induced by the feedback processes and the details of the gas dynamics that controls the star formation process through gravitational collapse. We perform a set of three-dimensional high-resolution numerical simulations of a turbulent, self-gravitating and magnetized interstellar medium within a $1\ \mathrm{kpc}$ stratified box with supernova feedback correlated with star-forming regions. In particular, we focus on the role played by the magnetic field and the feedback on the galactic vertical structure, the star formation rate (SFR) and the flow dynamics. For this purpose we vary their respective intensities. We extract properties of the dense clouds arising from the turbulent motions and compute power spectra of various quantities. Using a distribution of supernovae sufficiently correlated with the dense gas, we find that supernova explosions can reproduce the observed SFR, particularly if the magnetic field is on the order of a few $\mu G$. The vertical structure, which results from a dynamical and an energy equilibrium is well reproduced by a simple analytical model, which allows us to estimate the coupling between the gas and the supernovae. We found the coupling to be rather low and on the order of 1.5$\%$. Strong magnetic fields may help to increase this coupling by a factor of about 2-3. To characterize the flow we compute the power spectra of various quantities in 3D but also in 2D in order to account for the stratification of the galactic disc.