It all started with black holes

Enormous black holes that formed during the dark age of the universe, a lightless epoch before the first stars were born, may have predated the earliest galaxies, writes Steve Farrar.

Evidence presented to the American Astronomical Society meeting yesterday opens up the intriguing possibility that these giant black holes - some weighing a billion times more than the Sun - were the seeds of the galaxies that make up the universe today.

It might be that their immense gravitational pull helped to clump interstellar dust which ultimately formed the stars. This would mean that the universe we live in owes its structure to these giant black holes.

Douglas Richstone, professor of astronomy at the University of Michigan and leader of the research team, announced the discovery of three more supermassive black holes.

"The formation and evolution of galaxies are intimately connected to the presence of a central massive black hole," he said.

These black holes are far bigger and heavier than those formed by the collapse of massive stars. They are thought to be the powerhouses of quasars, the most brilliant, constant-light objects yet found in the early universe, and are believed to lurk in a more quiescent form in the heart of modern galaxies such as our own Milky Way.

Professor Richstone's observations hint that the black holes formed before the first galaxies inside which they can be seen to dwell.

"The brightest quasars seem to appear in the universe before most of the stars are born. The presence of the quasar is very important to the subsequent evolution of the galaxy, though whether it is the seed we simply do not know yet," said professor Richstone.