The Large Magellanic Cloud (LMC) is the largest of the dwarf galaxies orbiting the Milky Way (MW). It sits in a very interesting niche within the Local Group (LG), being both sufficiently different in mass than the MW to be an interesting comparison and sufficiently massive to be a major player in the MW's recent history and present state. In particular, it is massive enough to have a significant and observable effect on the MW itself and on stellar streams in the MW halo, though the extent of its influence depends on its mass. Its mass is also interesting as a benchmark against which we can interpret observations of more distant objects.
Bennet et al. (2022) recently measured proper motions (PMs) -- using HST, Gaia or both HST and Gaia together -- for a set of globular clusters (GCs) in the LMC. Supplemented with literature distances and line-of-sight velocities, this provides a catalogue of 6D phase space information for 32 LMC GCs. These are ideal dynamical tracers of the LMC’s potential.
In my talk, I will describe how we have used this set of tracers to estimate the anisotropy and mass of the LMC within 13 kpc, and then how we have used these estimates to extrapolate the LMC’s virial mass. This is the first time that this family of mass estimation methods has been applied to the LMC, and I will also compare our estimate against other estimates of the LMC’s mass via different methods and discuss the broader context of our results.
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