1.   Some of the resulting dense star clusters may undergo a gravitational collapse, which could produce a massive black hole in the core of a young galaxy.

2.   The distances of the young galaxies were confirmed by spectroscopic analyses of their light, as detected by the powerful Keck Telescope.

3.   The light is probably emitted by matter torn from young galaxies by the powerful gravity of a black hole.

4.   Young galaxies have a strong blue or ultraviolet tint, but at great distances, the ultraviolet wavelengths are absorbed by hydrogen in the galaxy and in intervening space.

5.   The very dust that obscures the young galaxies absorbs heat from the new stars and re-radiates it in faint, longer wavelengths that SCUBA picks up.