A New View of Galaxy Evolution from Submillimeter Surveys with SCUBA

Abstract

Our view of galaxy evolution has been dramatically enhanced by the recent deep field submm surveys carried out with the SCUBA camera on the JCMT. SCUBA has discovered a population of luminous infrared galaxies at redshifts ~1-4 that emit most of their energy at far-IR/submm wavelengths. The cumulative surface density of submm sources (~10,000 per sq.deg with S_850 > 1 mJy) appears to be sufficient to account for nearly all of the 850 micron extragalactic background. The SCUBA sources are plausibly the high-redshift counterparts of more local (z < 1) luminous infrared galaxies that have been identified in IRAS and ISO deep field surveys, the majority of which appear to be major mergers of gas-rich disks accompanied by dust-enshrouded nuclear starbursts and powerful AGN. The SCUBA sources are plausibly the progenitors of the present-day spheroidal population. This major event in galaxy evolution, equal in bolometric luminosity to that observed at optical wavelengths, is largely missed by current UV/optical surveys.