Galaxy mergers could limit star formation

Our astronomers have looked nine billion years into the past to find evidence that galaxy mergers in the early universe could shut down star formation and affect galaxy growth. Using a powerful Earth-based telescope they saw that a huge amount of star-forming gas was ejected into the universe by the coming together of two galaxies. The merger created a new galaxy called ID2299 at a time when the universe was only 4.5 billion years old. The researchers say that this event, combined with huge star formation in the galaxy's nuclear regions, could eventually deprive it of the fuel needed to make stars. This would stop star formation for several hundred million years, effectively halting the galaxy's development. Active black holes Astronomers observe many massive, dead galaxies containing very old stars in the nearby Universe and don't exactly know how these galaxies have been formed. Simulations suggest that winds generated by active black holes as they feed, or those created by intense star formation, are responsible for such deaths by expelling the gas from galaxies.