Topics

Black holes show up in early galaxies

1 April 2001

Radio observations have shown the presence of black holes in the centre of early
galaxies. The new results support the theory that supermassive black holes played a
crucial role in the formation of galaxies in the early universe.

Back in 1996 the
Hubble Space Telescope Science Institute released images of what became known as the
Hubble Deep Field – the deepest view of the universe ever taken. The images revealed
more than 1500 galaxies in the process of formation over 10 billion years ago. Today’s
radio images are three times as sharp.

The big surprise is that the radio source at
the centre of the early galaxies observed is so small – less than 600 light-years across.
The emission is so concentrated that it has to come from material orbiting a supermassive
black hole. Previously the radio emission was thought to come from the remnants of
short-lived massive stars.

The observations were made using the upgraded
European Very Long Base-line Interferometry network. The data from nine
radiotelescopes across Europe were combined to make one giant telescope of continental
dimensions.

bright-rec iop pub iop-science physcis connect