We present a high spatial resolution study, on scales of ∼100pc, of the
relationship between star-formation rate (SFR) and gas content within Local
Group galaxy M33. Combining deep SCUBA-2 observations with archival GALEX,
SDSS, WISE, Spitzer and submillimetre Herschel data, we are able to model the
entire SED from UV to sub-mm wavelengths. We calculate the SFR on a
pixel-by-pixel basis using the total infrared luminosity, and find a total SFR
of 0.17±0.06M⊙/yr, somewhat lower than our other two measures
of SFR -- combined FUV and 24μm SFR
(0.25−0.07+0.10M⊙/yr) and SED-fitting tool MAGPHYS
(0.33−0.06+0.05M⊙/yr). We trace the total gas using a
combination of the 21cm HI line for atomic hydrogen, and CO(J=2-1)
data for molecular hydrogen. We have also traced the total gas using dust
masses. We study the star-formation law in terms of molecular gas, total gas,
and gas from dust. We perform an analysis of the star-formation law on a
variety of pixel scales, from 25′′ to 500′′
(100pc to 2kpc). At kpc scales, we find that a linear Schmidt-type power law
index is suitable for molecular gas, but the index appears to be much higher
with total gas, and gas from dust. Whilst we find a strong scale dependence on
the Schmidt index, the gas depletion timescale is invariant with pixel scale.Comment: 19 pages, 15 figures, accepted for publication in MNRA