The Milky Way's Halo and Subhalos in Self-Interacting Dark Matter
  We perform high-resolution simulations of a MW-like galaxy in a
self-interacting cold dark matter model with elastic cross section over mass of
$1~\rm cm^2/g$ (SIDM) and compare to a model without self-interactions (CDM).
We run our simulations with and without a time-dependent embedded potential to
capture effects of the baryonic disk and bulge contributions. The CDM and SIDM
simulations with the embedded baryonic potential exhibit remarkably similar
host halo profiles, subhalo abundances and radial distributions within the
virial radius. The SIDM host halo is denser in the center than the CDM host and
has no discernible core, in sharp contrast to the case without the baryonic
potential (core size $\sim 7 \, \rm kpc$). The most massive subhalos (with
$V_{\mathrm{peak}}> 20 \, \rm km/s$) in our SIDM simulations, expected to host
the classical satellite galaxies, have density profiles that are less dense
than their CDM analogs at radii less than 500 pc but the deviation diminishes
for less massive subhalos. With the baryonic potential included in the CDM and
SIDM simulations, the most massive subhalos do not display the too-big-to-fail
problem. However, the least dense among the massive subhalos in both these
simulations tend to have the smallest pericenter values, a trend that is not
apparent among the bright MW satellite galaxies.
