SINFONI-HiZELS: The dynamics, merger rates & metallicity gradients of
  `typical' star-forming galaxies at $z$ = 0.8-2.2
  We present adaptive optics (AO) assisted SINFONI integral field unit (IFU)
spectroscopy of eleven H$\alpha$ emitting galaxies selected from the High-Z
Emission Line Survey (HiZELS). We obtain spatially resolved dynamics on
~kpc-scales of star-forming galaxies (stellar mass M$_\star$ = 10$^{9.5-10.5}$
M$_\odot$ and star formation rate SFR = 2-30 M$_\odot$ yr$^{-1}$) near the peak
of the cosmic star-formation rate history. Combining these observations with
our previous SINFONI-HiZELS campaign, we construct a sample of twenty
homogeneously selected galaxies with IFU AO-aided observations -- the `SHiZELS'
survey, with roughly equal number of galaxies per redshift slice, at $z$ = 0.8,
1.47, and 2.23. We measure the dynamics and identify the major kinematic axis
by modelling their velocity fields to extract rotational curves and infer their
inclination-corrected rotational velocities. We explore the stellar mass
Tully-Fisher relationship, finding that galaxies with higher velocity
dispersions tend to deviate from this relation. Using kinemetry analyses we
find that galaxy interactions might be the dominant mechanism controlling the
star-formation activity at $z$ = 2.23 but they become gradually less important
down to $z$ = 0.8. Metallicity gradients derived from the [NII]/H$\alpha$
emission line ratio show a median negative gradient for the SHiZELS survey of
$\Delta$log(O/H)/$\Delta$R = -0.026$\pm$0.008 dex kpc$^{-1}$. We find that
metal-rich galaxies tend to show negative gradients, whereas metal-poor
galaxies tend to exhibit positive metallicity gradients. This result suggests
that the accretion of pristine gas in the periphery of galaxies plays an
important role in replenishing the gas in `typical' star-forming galaxies.
