The Fate of Supernova-Heated Gas in Star-Forming Regions of the LMC: Lessons for Galaxy Formation?

TL;DR

This study uses 3D simulations to explore how supernova-driven outflows in the LMC interact with ram pressure, revealing that ram pressure can transform fountain flows into expelled gas, affecting galaxy evolution.

Contribution

The paper demonstrates through simulations that ram pressure can convert supernova-driven fountain flows into expelled gas, providing insights into galaxy gas dynamics and evolution.

Findings

Ram pressure can turn fountain flows into expelled gas.

Fountains near peak star formation can form part of the LMC filament.

Higher outflow activity may increase expelled gas mass.

Abstract

Galactic winds and fountains driven by supernova-heated gas play an integral role in re-distributing gas in galaxies, depositing metals in the circumgalactic medium (CGM), and quenching star formation. The interplay between these outflows and ram pressure stripping due to the galaxy's motion through an ambient medium may enhance these effects by converting fountain flows into expelled gas. In this paper, we present controlled, 3D simulations of ram pressure stripping combined with thermally driven, local outflows from clustered supernovae in an isolated disk galaxy modeled on the Large Magellanic Cloud (LMC), a dwarf satellite of the Milky Way on its first infall. Observational evidence of local outflows emanating from supergiant shells in the LMC and a trailing filament of HI gas originating from these regions - with no obvious Leading Arm counterpart - may represent a perfect example of this process. Our simulations present a proof-of-concept that ram pressure can convert fountain flows into expelled gas. We find that fountains launched near the peak star formation time of the LMC can comprise part of the LMC filament in the Trailing Stream, but with lower column densities than observed. Larger, more numerous outflows from the LMC may be possible and may contribute more mass, but higher inertia gas will lengthen the timescale for this gas to be swept away by ram pressure. Given the high resolution observations, increased knowledge of star formation histories, and growing evidence of multiphase, ionized outflows, the LMC is an ideal test-bed for future wind models.