Modeling the gravitational potential of a cosmological dark matter halo
  with stellar streams
  Stellar streams result from the tidal disruption of satellites and star
clusters as they orbit a host galaxy, and can be very sensitive probes of the
gravitational potential of the host system. We select and study narrow stellar
streams formed in a Milky-Way-like dark matter halo of the Aquarius suite of
cosmological simulations, to determine if these streams can be used to
constrain the present day characteristic parameters of the halo's gravitational
potential. We find that orbits integrated in static spherical and triaxial NFW
potentials both reproduce the locations and kinematics of the various streams
reasonably well. To quantify this further, we determine the best-fit potential
parameters by maximizing the amount of clustering of the stream stars in the
space of their actions. We show that using our set of Aquarius streams, we
recover a mass profile that is consistent with the spherically-averaged dark
matter profile of the host halo, although we ignored both triaxiality and time
evolution in the fit. This gives us confidence that such methods can be applied
to the many streams that will be discovered by the Gaia mission to determine
the gravitational potential of our Galaxy.
