Kiloparsec Scale Properties of Star-Formation Driven Outflows at z~2.3
  in the SINS/zC-SINF AO Survey
  We investigate the relationship between star formation activity and outflow
properties on kiloparsec scales in a sample of 28 star forming galaxies at
$z\sim$ 2-2.6, using adaptive optics assisted integral field observations from
SINFONI on the VLT. The narrow and broad components of the H$\alpha$ emission
are used to simultaneously determine the local star formation rate surface
density ($\Sigma_{\rm SFR}$), and the outflow velocity $v_{\rm out}$ and mass
outflow rate $\dot{M}_{\rm out}$, respectively. We find clear evidence for
faster outflows with larger mass loading factors at higher $\Sigma_{\rm SFR}$.
The outflow velocities scale as $v_{\rm out}$ $\propto$ $\Sigma_{\rm SFR}^{0.34
\pm 0.10}$, which suggests that the outflows may be driven by a combination of
mechanical energy released by supernova explosions and stellar winds, as well
as radiation pressure acting on dust grains. The majority of the outflowing
material does not have sufficient velocity to escape from the galaxy halos, but
will likely be re-accreted and contribute to the chemical enrichment of the
galaxies. In the highest $\Sigma_{\rm SFR}$ regions the outflow component
contains an average of $\sim$45% of the H$\alpha$ flux, while in the lower
$\Sigma_{\rm SFR}$ regions only $\sim$10% of the H$\alpha$ flux is associated
with outflows. The mass loading factor, $\eta$ = $\dot{M}_{\rm out}$/SFR, is
positively correlated with $\Sigma_{\rm SFR}$ but is relatively low even at the
highest $\Sigma_{\rm SFR}$: $\eta \lesssim$ 0.5 $\times$ (380 cm$^{-3}$/n$_e$).
This may be in tension with the $\eta$ $\gtrsim$ 1 required by cosmological
simulations, unless a significant fraction of the outflowing mass is in other
gas phases and has sufficient velocity to escape the galaxy halos.
