AGN Outflow Shocks on Bonnor-Ebert Spheres
  Feedback from Active Galactic Nuclei (AGN) and subsequent jet cocoons and
outflow bubbles can have a significant impact on star formation in the host
galaxy. To investigate feedback physics on small scales, we perform
hydrodynamic simulations of realistically fast AGN winds striking Bonnor-Ebert
(BE) spheres and examine gravitational collapse and ablation. We test AGN wind
velocities ranging from 300--3,000 km s$^{-1}$ and wind densities ranging from
0.5--10 $m_\mathrm{p}\,\mathrm{cm}^{-3}$. We include heating and cooling of
low- and high-temperature gas, self-gravity, and spatially correlated
perturbations in the shock, with a maximum resolution of 0.01 pc. We find that
the ram pressure is the most important factor that determines the fate of the
cloud. High ram pressure winds increase fragmentation and decrease the star
formation rate, but also cause star formation to occur on a much shorter time
scale and with increased velocities of the newly formed stars. We find a
threshold ram pressure of $\sim 2\times10^{-8}$ dyne cm$^{-2}$ above which
stars are not formed because the resulting clumps have internal velocities
large enough to prevent collapse. Our results indicate that simultaneous
positive and negative feedback will be possible in a single galaxy as AGN wind
parameters will vary with location within a galaxy.
