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 _ { SFR } ) , and the outflow velocity v _ { out } and mass outflow rate \dot { M } _ { out } , respectively .
We find clear evidence for faster outflows with larger mass loading factors at higher \Sigma _ { SFR } .
The outflow velocities scale as v _ { out } \propto \Sigma _ { 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 _ { SFR } regions the outflow component contains an average of \sim 45 % of the H \alpha flux , while in the lower \Sigma _ { SFR } regions only \sim 10 % of the H \alpha flux is associated with outflows .
The mass loading factor , \eta = \dot { M } _ { out } /SFR , is positively correlated with \Sigma _ { SFR } but is relatively low even at the highest \Sigma _ { 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 .