Constraining the Milky Way halo kinematics via its Linear Response to the Large Magellanic Cloud

Understand

We model the response of spherical, non-rotating Milky Way (MW) dark matter and stellar halos to the Large Magellanic Cloud (LMC) using the matrix method of linear response theory.

• Our computations reproduce the main features of the dark halo response from simulations.
• We show that these features can be well separated by a harmonic decomposition: the large scale over/underdensity in the halo (associated with its reflex motion) corresponds to the $\ell=1$ terms, and the local overdensity to the $\ell\geq2$ multipoles.
• Moreover, the dark halo response is largely dominated by the first order 'forcing' term, with little influence from self-gravity.