First Constraints on Source Counts at 350 μm

We have imaged a ~6 arcmin2 region in the Bootes Deep Field using the 350 μm-optimized second-generation Submillimeter High Angular Resolution Camera (SHARC II), achieving a peak 1 σ sensitivity of ~5 mJy. We detect three sources above 3 σ, and determine a spurious source detection rate of 1.09 in our maps. In the absence of 5 σ detections, we rely on deep 24 μm and 20 cm imaging to deduce which sources are most likely to be genuine, giving two real sources. From this we derive an integral source count of 0.84 sources arcmin-2 at S > 13 mJy, which is consistent with 350 μm source count models that have an IR-luminous galaxy population evolving with redshift. We use these constraints to consider the future for ground-based short-submillimeter surveys.