We present adaptive optics assisted integral field spectroscopy of nine H \alpha -selected galaxies at z = 0.84–2.23 drawn from the HiZELS narrow-band survey .
Our observations map the kinematics of these star-forming galaxies on \sim kpc-scales .
We demonstrate that within the ISM of these galaxies , the velocity dispersion of the star-forming gas ( \sigma ) follows a scaling relation \sigma \propto \Sigma _ { SFR } ^ { 1 / n } + constant ( where \Sigma _ { SFR } is the star formation surface density and the constant includes the stellar surface density ) .
Assuming the disks are marginally stable ( Toomre Q = 1 ) , this follows from the Kennicutt-Schmidt relation ( \Sigma _ { SFR } = A \Sigma _ { gas } ^ { n } ) , and we derive best fit parameters of n = 1.34 \pm 0.15 and A = 3.4 _ { -1.6 } ^ { +2.5 } \times 10 ^ { -4 } M _ { \odot } yr ^ { -1 } kpc ^ { -2 } , consistent with the local relation , and implying cold molecular gas masses of M _ { gas } = 10 ^ { 9 - 10 } M _ { \odot } and molecular gas fractions M _ { gas } / ( M _ { gas } + M _ { \star } ) = 0.3 \pm 0.1 , with a range of 10 – 75 % .
We also identify eleven \sim kpc-scale star-forming regions ( clumps ) within our sample and show that their sizes are comparable to the wavelength of the fastest growing mode .
The luminosities and velocity dispersions of these clumps follow the same scaling relations as local H ii regions , although their star formation densities are a factor \sim 15 \pm 5 \times higher than typically found locally .
We discuss how the clump properties are related to the disk , and show that their high masses and luminosities are a consequence of the high disk surface density .