Hubble peers into the core of a distant galaxy

An initial look at the pictures favours the idea that titanic black holes at the centres of galaxies did not exist before the galaxy was born but evolved within the galaxy by swallowing stars and gas.

How big the black hole becomes depends upon the food supply that in turn depends upon the size of the galaxy.

Astronomers believe that black holes in small galaxies went relatively undernourished, weighing in at a mere few million solar masses.

Formation and growth

Black holes in the centres of giant galaxies however, some over one billion solar masses, were so engorged with gas they once blazed as quasars, the brightest objects in the cosmos.

"This supports the original theory of how black holes got their masses. It suggests that the major events that made a galaxy and the ones that made its black hole shine as a quasar were the same events," says John Kormendy of the University of Texas at Austin.

Though this secret relationship between a black hole and its host galaxy has been suspected for the past several years, it is bolstered by the Hubble discovery of 10 more supermassive black holes in galaxy centres, raising the total to more than 30 black holes now available for study.

"For the first time we can put strong constraints on the relationship between galaxy formation and black hole formation and growth," says Kormendy.