2017ApJ...850...68C

We present accurate resolved WISE photometry of galaxies in the combined SINGS and KINGFISH sample. The luminosities in the W3 12 µm and W4 23 µm bands are calibrated to star formation rates (SFRs) derived using the total infrared luminosity, avoiding UV/optical uncertainties due to dust extinction corrections. The W3 relation has a 1σ scatter of 0.15 dex that is over nearly 5 orders of magnitude in SFR and 12 µm luminosity, and a range in host stellar mass from dwarfs (10⁷ M_☉) to ∼3×M^*^ (10^11.5 M_☉) galaxies. In the absence of deep silicate absorption features and powerful active galactic nuclei, we expect this to be a reliable SFR indicator chiefly due to the broad nature of the W3 band. By contrast, the W4 SFR relation shows more scatter (1σ =0.18 dex). Both relations show reasonable agreement with radio-continuum-derived SFRs and excellent accordance with so-called "hybrid" Hα + 24 µm and FUV+24 µm indicators. Moreover, the WISE SFR relations appear to be insensitive to the metallicity range in the sample. We also compare our results with IRAS-selected luminous infrared galaxies, showing that the WISE relations maintain concordance, but systematically deviate for the most extreme galaxies. Given the all-sky coverage of WISE and the performance of the W3 band as an SFR indicator, the L_12µm_ SFR relation could be of great use to studies of nearby galaxies and forthcoming large-area surveys at optical and radio wavelengths.