Could the Magellanic Clouds be tidal dwarves expelled from a past-merger
  event occurring in Andromeda?
  The Magellanic Clouds are often considered as outliers in the satellite
system of the Milky Way because they are irregular and gas-rich galaxies. From
their large relative motion, they are likely from their first pass near the
Milky Way, possibly originating from another region of the Local Group or its
outskirts. M31 could have been in a merger stage in its past and we investigate
whether or not the Large Magellanic Cloud could have been a tidal dwarf
expelled during this event. Such an hypothesis is tested in the frame of
present-day measurements and uncertainties of the relative motions of LMC and
M31. Our method is to trace back the LMC trajectory using several thousands of
different configurations that sample the corresponding parameter space. We find
several configurations that let LMC at 50 kpc from M31, 4.3 to 8 Gyrs ago,
depending on the adopted shape of the Milky Way halo. For all configurations,
the LMC velocity at such a location is invariably slightly larger than the
escape velocity at such a radius. The preferred solutions correspond to a
spherical to prolate Milky Way halo, predicting a transversal motion of M31 of
less than 107 km/s and down to values that are close to zero. We conclude that
from present-day measurements, Magellanic Clouds could well be tidal dwarves
expelled from a former merger events occurring in M31.
