We present the complete submillimeter data for the Canada-UK Deep Submillimeter Survey (CUDSS) 3h field. The observations were taken with the Submillimeter Common-User Bolometric Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT) on Mauna Kea. The 3h field is one of two main fields in our survey and covers 60 arcmin2 to a 3 σ depth of ~3 mJy. In this field we have detected 27 sources above 3 σ and 15 above 3.5 σ. We assume that the differential source counts follow the form N(S) ∝ S-α and measure α = 3.3, in good agreement with previous studies. We estimate that SCUBA sources brighter than 3 mJy are responsible for ~13% of the extragalactic background at 850 μm (after correcting for flux boosting, 20% with no correction), which is in general agreement with previous estimates made by other groups. Using preliminary Infrared Space Observatory 15 μm maps and VLA 1.4 GHz data, we have identified counterparts for 10 objects and have detected two sources at 450 μm. With this information we estimate a lower limit on the median redshift of the sample of z > 1.4 with 6%-10% lying at z < 1. We have attempted to measure the angular clustering of S850 μm > 3 mJy sources using the source catalogs from the CUDSS two main fields, the 3h and 14h fields, and find ω(θ) = 4.4 ± 2.9θ-0.8, or a 3 σ upper limit on the clustering amplitude of less than 8.7 arcsec0.8. This is consistent with clustering at least as strong as that seen for the Lyman break galaxy population and the extremely red objects. Since SCUBA sources are selected over a broader range in redshifts than these two populations, the strength of the true spatial clustering is expected to be correspondingly stronger.

We have used 850 μm maps obtained as part of the Canada-UK Deep Submillimeter Survey (CUDSS) to investigate the submillimeter properties of Lyman break galaxies (LBGs). We used three samples of LBGs: two from the Canada-France Deep Fields (CFDF) survey covering CUDSS 14 and CUDSS 03, and one from Steidel and collaborators also covering CUDSS 14. We measure a mean flux from both CFDF LBG samples at a level of ~2 σ of 0.414 ± 0.263 mJy for CUDSS 03 and 0.382 ± 0.206 mJy for CUDSS 14, but the Steidel et al. sample is consistent with zero flux. From this we place upper limits on the Lyman break contribution to the 850 μm background of ~20%. We have also measured the cross-clustering between the LBGs and the SCUBA sources. From this measurement we infer a large clustering amplitude of r0 = 11.5 ± 3.0 ± 3.0 h-1 Mpc for the Steidel et al. sample (where the first error is statistical and the second systematic), r0 = 4.5 ± 7.0 ± 5.0 h-1 Mpc for CFDF 14, and r0 = 7.5 ± 7.0 ± 5.0 h-1 Mpc for CFDF 03. The Steidel et al. sample, for which we have the most significant detection of clustering, is also the largest of the three samples and has spectroscopically confirmed redshifts

Deep surveys of the sky at millimeter wavelengths have revealed a population of ultra-luminous infrared galaxies (ULIRGs) at high redshifts. These appear similar to local objects of similar luminosities (such as Arp220) but are much more ‘important’ at high redshift than at low resdhift, in the sense that they represent a much larger fraction of the total luminous output of the distant Universe than they do locally. In fact the ULIRGs at high redshift are producing a significant fraction (≥ 15%) of the total luminous output of the Universe averaged over all wavelengths and all epochs. The high-z ULIRGs could plausibly be responsible for producing the metal-rich spheroidal components of galaxies, including the bulges of spiral galaxies. In this case we would infer from the redshift distribution of the sources that much of this activity is probably happening relatively recently at z ≤ 2.

We present a high-resolution millimetre interferometric image of the brightest SCUBAselected galaxy from the Canada-UK deep SCUBA survey (CUDSS). We make a very clear detection at 1.3 mm, but fail to resolve any structure in the source. The interferometric position is within 1.5 arcsec of the SCUBA 850 � m centroid, and also within 1.5 arcsec of a 44 � Jy radio source and a very faint, extremely red galaxy which we had previously identified as the submillimetre source. We also present new optical and infrared imaging, and infrared spectroscopy of this source. We model the overall spectral energy distribution and conclude that it lies within the redshift range 2< z < 4.5. The submm/FIR luminosity of CUDSS14A is very weakly dependent on redshift within the constrained range, and is roughly 4×10 12 L⊙ (for H0=75 and an assumed Arp220-like spectrum), which implies a star-formation rate �1000 M⊙ yr −1 . We derive an approximate gas mass of � 10 10 M⊙ which would imply the current starforming activity cannot be sustained for longer than about 10 million years. With the present data however we are unable to rule out a significant AGN contribution to the total luminosity.