WASHINGTON – When galaxies initially formed, they weren't the first in the cosmic neighborhood.
The supermassive black holes, which reside at the center of galaxies, probably moved in first, a new astronomy study suggests.
Measurements from radio telescopes looking at the early universe hint at that answer to this cosmic chicken-and-egg question of whether the galaxy or its supermassive black hole existed first.
The new research presented Wednesday at the American Astronomical Society in Long Beach, Calif., is preliminary, however. It's based on measurements of four black holes that date to about 1 to 2 billion years after the Big Bang.
Previous measurements estimating the mass of galaxies and black holes showed a nice steady relationship that didn't give a clue as to which came first.
But when astronomers used radio waves to look back to 1 to 2 billion years after the Big Bang, they found four supermassive black holes that were far larger than the standard plot would show.
That likely means that they formed before the galaxies, said study lead author Chris Carilli of the National Radio Astronomy Observatory in Socorro, N.M.
But after that, astronomers are still clueless on why this happens and how the galaxies formed around them.
"I don't think it clears the murky waters of our understanding of galaxy formation," Carilli said in a news conference.