More and more, black holes are being found at the center of galaxies. As the close relationship between black holes and galaxies has emerged, astronomers have debated which of the two came first.

One model holds that mass builds up at the center of galaxies, eventually collapsing so black holes can form. Another holds the opposite -- that black holes exist first, and their immense gravity draws gas, dust, and stars together, causing galaxies to form.

A study at Ohio State University has uncovered more evidence that black holes form before the galaxies that contain them. Marianne Vestergaard came to this conclusion when she studied a collection of very energetic, active galaxies known as quasars as they appeared some 12 billion years ago, when the universe was only one billion years old. While the quasars were obviously young -- they contained large stellar nurseries in which new stars were forming -- each also contained a very massive, fully formed black hole. Part of her data came from the Sloan Digital Sky Survey. >from *Black holes form first, galaxies follow. New quasar study*, january 8, 2003

related context
> milky way center: a supermassive black hole. october 22, 2002
> Chandra image of Milky Way center. august 22, 2000
> Sloan Digital Sky Survey

imago
> galaxies sphincters