SIMBAD references

The ambient interstellar environment of wind- and supernova-driven superbubbles strongly affects their evolution, but its properties are rarely well determined. We have therefore obtained H I aperture synthesis imaging of the environment around three similar optically selected superbubble nebulae in the Large Magellanic Cloud. The resulting H I maps show that the ambient gas distributions around these superbubbles differ to an extreme: DEM L25 shows no neutral shell component but is nestled within an H I hole; DEM L50 shows a massive neutral shell component but is otherwise within an H I void; and DEM L301 shows no correspondence at all between the optical nebula and H I distribution. There is also poor correspondence between the H I and optical kinematics. These results strongly caution against inferring properties of the ambient neutral environment of individual superbubbles without direct observations. Finally, all three objects show some evidence of shock activity.