By studying how some of these distant starburst galaxies are clustered together, astronomers have found that they eventually become so-called giant elliptical galaxies — the most massive galaxies in today’s Universe.

The galaxies are so distant that their light has taken around ten billion years to reach us, so we see them as they were about ten billion years ago. Because of this extreme distance, the infrared light from dust grains heated by starlight is redshifted into longer wavelengths, and the dusty galaxies are therefore best observed in submillimetre wavelengths of light. The galaxies are thus known as submillimetre galaxies.