Cosmic climate change in early universe 'may have stunted black holes'
London: The early universe, which was warmed by the greediest of black holes, could have stunted the growth of the rest, a new study has revealed.
Astronomical surveys suggest that supermassive black holes, which are the largest type of black holes in a galaxy and weight a billion times more than the sun, had formed before the universe was a billion years old.
The seeds for these gigantic things are thought to be black holes weighing just a few tens of solar masses. To get so big in less than a billion years, the seed black holes must have taken in gas at a colossal rate.
In this scenario, one would expect to see a distribution of black hole masses, with intermediate-sized black holes in orders of magnitude greater than what we see in our local universe.
Something must have limited the growth of these black holes, and now Takamitsu Tanaka at the Max Planck Institute for Astrophysics in Garching, Germany, and colleagues have a climate-based explanation for this phenomenon.
They have shown that an abnormal amount of X-rays emitted as the supermassive black holes swallowed gas would have heated up the universe.
Black holes need cool gas to grow so this would have slowed down the growth of other black holes in smaller protogalaxies, even as the growth of black holes in the most massive protogalaxies continued quickly.
“This global warming process could have basically quenched the latecomers,” New Scientist quoted Tanaka as saying.
“The early ones end up being the monsters and they prevent the overgrowth of the rest,” Tanaka added.