Sub-millimeter Galaxies

Need to survey the sky in the sub-mm to find high redshift dusty starburst galaxies. Hard, because large area sub-mm detectors are very hard to build. Technology only available over the past 15 years or so. But we're now finding these galaxies! Deep imaging in the optical can sometime reveals these sources. Can get redshifts either from optical or radio emission lines. Properties: redshift distribution: z=1-4 very high star formation rates (> 1000 Msun/yr) massive (few x 1011 Msun)	Sub-mm images of galaxies detected by the SCUBA camera.
What do they look like optically?
(from Smail etal 2004, ApJ, 616, 71)
If they are massive galaxies merging at high redshift, what would these galaxies be today?