On the Tidal Formation of Dark Matter Deficient Galaxies
  Previous studies have shown that dark matter deficient galaxies (DMDG) such
as NGC1052-DF2 (hereafter DF2) can result from tidal stripping. An important
question, though, is whether such a stripping scenario can explain DF2's large
specific frequency of globular clusters (GCs). After all, tidal stripping and
shocking preferentially remove matter from the outskirts. We examine this using
idealized, high-resolution simulations of a regular dark matter dominated
galaxy that is accreted onto a massive halo. As long as the initial
(pre-infall) dark matter halo of the satellite is cored, which is consistent
with predictions of cosmological, hydrodynamical simulations, the tidal remnant
can be made to resemble DF2 in all its properties, including its GC population.
The required orbit has a peri-centre at the 8.3 percentile of the distribution
for subhaloes at infall, and thus is not particularly extreme. On this orbit
the satellite loses 98.5 (30) percent of its original dark matter (stellar)
mass, and thus evolves into a DMDG. The fraction of GCs that is stripped off
depends on the initial radial distribution. If, at infall, the median projected
radius of the GC population is roughly two times that of the stars, consistent
with observations of isolated galaxies, only $\sim 20$ percent of the GCs are
stripped off. This is less than for the stars, which is due to dynamical
friction counteracting the tidal stirring. We predict that, if indeed DF2 was
crafted by strong tides, its stellar outskirts should have a very shallow
metallicity gradient.
