JINGLE, a JCMT legacy survey of dust and gas for galaxy evolution studies: II. SCUBA-2 850$\mu$m data reduction and dust flux density catalogues

We present the SCUBA-2 850 µ m component of JINGLE, the new JCMT large survey for dust and gas in nearby galaxies, which with 193 galaxies is the largest targeted survey of nearby galaxies at 850 µ m. We provide details of our SCUBA-2 data reduction pipeline, optimised for slightly extended sources, and including a calibration model adjusted to match conventions used in other far-infrared data. We measure total integrated fluxes for the entire JINGLE sample in 10 infrared/submillimetre bands, including all WISE, Herschel -PACS, Herschel -SPIRE and SCUBA-2 850 µ m maps, statistically accounting for the contamination by CO( J =3-2) in the 850 µ m band. Of our initial sample of 193 galaxies, 191 are detected at 250 µ m with a ≥ 5 σ significance. In the SCUBA-2 850 µ m band we detect 126 galaxies with ≥ 3 σ significance. The distribution of the JINGLE galaxies in far-infrared/sub-millimetre colour-colour plots reveals that the sample is not well fit by single modified-blackbody models that assume a single dust-emissivity index ( β ). Instead, our new 850 µ m data suggest either that a large fraction of our objects require β β for JINGLE-like galaxies. For JINGLE the FIR colours correlate more strongly with star-formation rate surface-density rather than the stellar surface-density, suggesting heating of dust is greater due to younger rather than older stellar-populations, consistent with the low proportion of early-type galaxies in the sample.