Black holes 'came before galaxies'
Astronomers claim to have finally solved the cosmic chicken-egg problem by concluding that black holes came before galaxies.india Updated: Jan 07, 2009 18:31 IST
Astronomers claim to have finally solved the cosmic chicken-egg problem by concluding that black holes came before galaxies. For several years, researchers have known galaxies and black holes must have co-evolved. If not all, at least our own -- the Milky Way -- is believed to have massive black holes at its cores.
Now, an international team, studying on the first billion years of the universe's history, has found that black holes predate galaxies. "It looks like the black holes came first. The evidence is piling up," 'The Daily Telegraph' quoted Dr Chris Carilli from the US National Radio Astronomy Observatory, who led the team, as saying.
In their radio telescope observations, reaching back almost to the birth of the first galaxies, the team found that radio waves received from those and travelling at the speed of light were emitted only about a billion years after the Big Bang which started the universe. (MORE) PRI UK-BLACKHOLES 2 LAST The young distant galaxies had much larger black holes in relation to their bulge mass than older and closer galaxies -- "The implication is the black holes started growing first," said team member Dr Fabian Walter of Max-Planck Institute for Radioastronomy in Germany.
According to the astronomers, the next challenge is to work out how the black hole and the bulge affect each other's growth. "Powerful new telescopes now under construction will help to unravel the mystery," Dr Carilli said. He added: "To understand how the universe got to be the way it is today, we must understand how the first stars and galaxies were formed when the universe was young.
With the new observatories we'll have in the next few years, we'll have the opportunity to learn important details from the era when the universe was only a toddler compared to today's adult." The findings of the study were presented at American Astronomical Society's annual meeting in California.