PPT Slide
What do these things look like morphologically? We have NICMOS imaging of B1: this picture overlays this (red) on the Ly-alpha (blue) and R-band (green). It consists of two compact objects with very red colours separated by about 4 kpc (0.8 arcsec). R-band emission (rest-frame UV, so tracing star formation) is very weak, but mostly comes from a tail extending about 10kpc south - a possible tidal tail. This tail coincides with the peak of the Ly-alpha emission.