Characterizing the Shape of the Large Magellanic Cloud's Bowshock

Abstract

The Circumgalactic Medium (CGM) surrounding our Milky Way plays an essential role in supplying the fuel needed to drive and sustain star formation in our Galaxy. However, the CGM is extremely diffuse ( 1028 g cm-3), and therefore difficult to probe. Consequently, we know little about the structure, mass profile or evolution of the CGM. Using hydrodynamic simulations, we study the impact of the supersonic motions of the Large Magellanic Cloud (LMC), the largest satellite galaxy of the Milky Way, on the structure of the CGM. We conclude that the LMC must induce a large bow shock in the CGM and use simulations to characterize its size, shape, temperature, and density structure. Using these properties, we propose possible observational signatures that could be used to confirm the existence of the shock, and illustrate how the shock may provide a tool to probe the CGM. These results illustrate that the CGM is a dynamic system, affected not only by outflows from the host galaxy, but also by the motions of the satellites that orbit within it.