2013ApJ...778...51K

Submillimeter excess emission has been reported at 500 µm in a handful of local galaxies, and previous studies suggest that it could be correlated with metal abundance. We investigate the presence of an excess submillimeter emission at 500 µm for a sample of 20 galaxies from the Key Insights on Nearby Galaxies: a Far Infrared Survey with Herschel (KINGFISH) that span a range of morphologies and metallicities (12 + log (O/H) = 7.8-8.7). We probe the far-infrared (IR) emission using images from the Spitzer Space Telescope and Herschel Space Observatory in the wavelength range 24-500 µm. We model the far-IR peak of the dust emission with a two-temperature modified blackbody and measure excess of the 500 µm photometry relative to that predicted by our model. We compare the submillimeter excess, where present, with global galaxy metallicity and, where available, resolved metallicity measurements. We do not find any correlation between the 500 µm excess and metallicity. A few individual sources do show excess (10%-20%) at 500 µm; conversely, for other sources, the model overpredicts the measured 500 µm flux density by as much as 20%, creating a 500 µm "deficit." None of our sources has an excess larger than the calculated 1σ uncertainty, leading us to conclude that there is no substantial excess at submillimeter wavelengths at or shorter than 500 µm in our sample. Our results differ from previous studies detecting 500 µm excess in KINGFISH galaxies largely due to new, improved photometry used in this study.