We present first results from the KMOS Redshift One Spectroscopic Survey ( KROSS ) , an ongoing large kinematical survey of a thousand , z \sim 1 star forming galaxies , with VLT KMOS .
Out of the targeted galaxies ( \sim 500 so far ) , we detect and spatially resolve H \alpha  emission in \sim 90 \% and 77 % of the sample respectively .
Based on the integrated H \alpha  flux measurements and the spatially resolved maps we derive a median star formation rate ( SFR ) of \sim 7.0 M _ { \odot } yr ^ { -1 } and a median physical size of \langle r ^ { \prime } _ { 1 / 2 } \rangle = 5.1 kpc .
We combine the inferred SFRs and effective radii measurements to derive the star formation surface densities ( \Sigma _ { SFR } ) and present a “ resolved ” version of the star formation main sequence ( MS ) that appears to hold at sub-galactic scales , with similar slope and scatter as the one inferred from galaxy integrated properties .
Our data also yield a trend between \Sigma _ { SFR } Â and \Delta ( sSFR ) ( distance from the MS ) suggesting that galaxies with higher sSFR are characterised by denser star formation activity .
Similarly , we find evidence for an anti-correlation between the gas phase metallicity ( Z ) and the \Delta ( sSFR ) , suggesting a 0.2 dex variation in the metal content of galaxies within the MS and significantly lower metallicities for galaxies above it .
The origin of the observed trends between \Sigma _ { SFR } - \Delta ( sSFR ) and Z - \Delta ( sSFR ) could be driven by an interplay between variations of the gas fraction or the star formation efficiency of the galaxies along and off the MS. To address this , follow-up observations of the our sample that will allow gas mass estimates are necessary