Submillimeter Detections of Spitzer Space Telescope Galaxy Populations

We present submillimeter statistical detections of galaxies discovered in the 5′ × 5′ Spitzer Early Release Observations (to ∼4-15 μJy 5 σ at 3.6-8 μm, 170 μJy at 24 μm) through a stacking analysis of our reanalyzed SCUBA 8 mJy survey maps and a Spitzer identification of a new submillimeter point source in the 8 mJy survey region. For sources detected at 5.8 or 8 μm (154 and 111 sources, respectively), we detect positive skews in the submillimeter flux distributions at 99.2%-99.8% confidence using Kolmogorov-Smirnov tests, at both 850 and 450 μm. We also marginally detect the Spitzer 24 μm galaxies at 850 μm at 97% confidence and place limits on the mean submillimeter fluxes of the 3.6 and 4.5 μm sources. Integrating the submillimeter fluxes of the Spitzer populations, we find the 5.8 μm galaxies contribute 0.12 ± 0.05 nW m-2 sr-1 to the 850 μm background and 2.4 ± 0.7 nW m-2 sr-1 to the 450 μm background; similar contributions are made by the 8 μm-selected sample. We infer that the populations dominating the 5.8 and 8 μm extragalactic background light also contribute around a quarter of the 850 μm background and the majority of the 450 μm background.