text: 397,287,1321399158037749760,718084071,Denis Erkal,"Paper day! We find evidence that the inner Milky Way is sloshing about with respect to the outer stellar halo (&gt;50 kpc) due to the LMC. We consider 492 stars in the outer stellar halo with measured radial velocities and see a clear dipole on the sky. 1/n <LINK> <LINK> The stars in the North are redshifted on average and the stars in the South are blueshifted on average, consistent with us moving downwards at ~30 km/s with respect to the outer stellar halo. This matches the predicted effect of the LMC. 2/n <LINK> The basic picture is that as the LMC falls in, it pulls on the Milky Way. Stars in the inner ~30 kpc have a short enough orbital period that they respond adiabatically while stars beyond this roughly stand still. As a result, the inner MW moves with respect to the outer halo. 3/n The measured radial velocity signal is consistent with a broad range of LMC masses, including those we measured with tidal streams around the Milky Way. 4/n <LINK> We also took a gander at the proper motions of these stars with Gaia DR2. The measurements are broadly consistent although since the predicted effect is so small, it's difficult to tell. Hopefully with Gaia EDR3 we can measure this more precisely. 5/n <LINK> This means that the outskirts of our Galaxy are really out of equilibrium which must be accounted for when modelling any tracers out there. In addition, it means that the inner Milky Way is not an inertial reference frame but instead has been substantially accelerated. 6/n See <LINK> <LINK> <LINK> for more details on the mechanism of the LMC's effect @iHinkthere4iam Good question. We didn't try to fit this direction since the predicted effect on the radial velocity isn't just a dipole. Given that we see the signal over a lot of the sky, I'd guess the direction could be measured with an uncertainty of ~10s of degrees even with current data. @iHinkthere4iam A very precise measure of the orientation could perhaps tell us something about the dark matter around the LMC (which would include SMC material) but I'd guess we would need a much bigger sample to learn about such subtle features.",https://arxiv.org/abs/2010.13789,"A wealth of recent studies have shown that the LMC is likely massive, with a halo mass $>10^{11} M_\odot$. One consequence of having such a nearby and massive neighbour is that the inner Milky Way is expected to be accelerated with respect to our Galaxy's outskirts (beyond $\sim 30$ kpc). In this work we compile a sample of $\sim 500$ stars with radial velocities in the distant stellar halo, $r_{\rm GC}> 50$ kpc, to test this hypothesis. These stars span a large fraction of the sky and thus give a global view of the stellar halo. We find that stars in the Southern hemisphere are on average blueshifted, while stars in the North are redshifted, consistent with the expected, mostly downwards acceleration of the inner halo due to the LMC. We compare these results with simulations and find the signal is consistent with the infall of a $1.5\times10^{11} M_\odot$ LMC. We cross-match our stellar sample with \textit{Gaia} DR2 and find that the mean proper motions are not yet precise enough to discern the LMC's effect. Our results show that the outer Milky Way is significantly out of equilibrium and that the LMC has a substantial effect on our Galaxy. ",Detection of the LMC-induced sloshing of the Galactic halo,9,"['Paper day! We find evidence that the inner Milky Way is sloshing about with respect to the outer stellar halo (&gt;50 kpc) due to the LMC.\n\nWe consider 492 stars in the outer stellar halo with measured radial velocities and see a clear dipole on the sky. 1/n\n\n<LINK> <LINK>', 'The stars in the North are redshifted on average and the stars in the South are blueshifted on average, consistent with us moving downwards at ~30 km/s with respect to the outer stellar halo. This matches the predicted effect of the LMC. 2/n https://t.co/fcBm7prClO', 'The basic picture is that as the LMC falls in, it pulls on the Milky Way. Stars in the inner ~30 kpc have a short enough orbital period that they respond adiabatically while stars beyond this roughly stand still. As a result, the inner MW moves with respect to the outer halo. 3/n', 'The measured radial velocity signal is consistent with a broad range of LMC masses, including those we measured with tidal streams around the Milky Way. 4/n https://t.co/oZuaJxhu6D', ""We also took a gander at the proper motions of these stars with Gaia DR2. The measurements are broadly consistent although since the predicted effect is so small, it's difficult to tell. Hopefully with Gaia EDR3 we can measure this more precisely. 5/n https://t.co/m2IAJ8JU4K"", 'This means that the outskirts of our Galaxy are really out of equilibrium which must be accounted for when modelling any tracers out there. In addition, it means that the inner Milky Way is not an inertial reference frame but instead has been substantially accelerated. 6/n', ""See https://t.co/OeNz3cub98 https://t.co/VA1DcSYsJc\nhttps://t.co/SMjZbnuemy\nfor more details on the mechanism of the LMC's effect"", ""@iHinkthere4iam Good question. We didn't try to fit this direction since the predicted effect on the radial velocity isn't just a dipole. Given that we see the signal over a lot of the sky, I'd guess the direction could be measured with an uncertainty of ~10s of degrees even with current data."", ""@iHinkthere4iam A very precise measure of the orientation could perhaps tell us something about the dark matter around the LMC (which would include SMC material) but I'd guess we would need a much bigger sample to learn about such subtle features.""]",20,10,2120