Filaments in Galactic Winds Driven by Young Stellar Clusters

TL;DR

This paper models the formation of Hα-emitting filaments in the starburst galaxy M82 as a result of radiative interactions between winds from young stellar clusters, using 3D simulations to match observations.

Contribution

It introduces a criterion for radiative interactions between cluster winds and demonstrates its effectiveness in predicting filament formation in galactic winds.

Findings

Radiative cluster wind interactions produce filamentary structures consistent with M82 observations.

Non-radiative models fail to produce filamentary structures.

The interaction criterion depends on mass loss rate, wind velocity, and cluster separation.

Abstract

The starburst galaxy M82 shows a system of H$\alpha$-emitting filaments which extend to each side of the galactic disk. We model these filaments as the result of the interaction between the winds from a distribution of Super Stellar Clusters (SSCs). We first derive the condition necessary for producing a radiative interaction between the cluster winds (a condition which is met by the SSC distribution of M82). We then compute 3D simulations for SSC wind distributions which satisfy the condition for a radiative interaction, and also for distributions which do not satisfy this condition. We find that the highly radiative models, that result from the interaction of high metallicity cluster winds, produce a structure of H$\alpha$ emitting filaments, which qualitatively agrees with the observations of the M82, while the non-radiative SSC wind interaction models do not produce filamentary structures. Therefore, our criterion for radiative interactions (which depends on the mass loss rate and the terminal velocity of the SSC winds, and the mean separation between SSCs) can be used to predict whether or not an observed galaxy should have associated H$\alpha$ emitting filaments.