The Bolocam 1.1 mm Lockman Hole galaxy survey:: Sharc II 350 μm photometry and implications for spectral models, dust temperatures, and redshift estimation

We present 350 mu m photometry of all 17 galaxy candidates in the Lockman Hole detected in a 1.1 mm Bolocam survey. Several of the galaxies were previously detected at 850 mu m, at 1.2 mm, in the infrared by Spitzer, and in the radio. Nine of the Bolocam galaxy candidates were detected at 350 mu m, and two new candidates were serendipitously detected at 350 mu m (bringing the total in the literature detected in this way to three). Five of the galaxies have published spectroscopic redshifts, enabling investigation of the implied temperature ranges and a comparison of photometric redshift techniques. For z approximate to 2.5 thermally emitting galaxies, lambda = 350 mu m lies near the spectral energy distribution peak. Thus, luminosities can be measured without extrapolating to the peak from detection wavelengths of lambda = 850 mu m. Characteristically, the galaxy luminosities lie in the range 1.0 - 1.2 x 10(13) L circle dot, with dust temperatures in the range 40 - 70 K, depending on the choice of spectral index and wavelength of unit optical depth. The implied dustmasses are (3 - 5) x 10(8) M circle dot. We find that the far-infrared to radio relation for star-forming ULIRGs systematically overpredicts the radio luminosities and overestimates redshifts on the order of Delta z approximate to 1, whereas redshifts based on either submillimeter data alone or the 1.6 mu m stellar bump and PAH features are more accurate.