Monster black holes were forming when the universe was young — just a few percent of its current age. And that’s a problem. Most ideas of how supermassive black holes form can’t explain such a rapid birth. But a new idea says the black holes could have had some help: the gravitational pull of dark matter.
Supermassive black holes are millions or billions of times as massive as the Sun. They inhabit the cores of most large galaxies, including our own. And they’ve been seen in galaxies that were forming as little as 800 million years after the Big Bang — 13 billion years ago.
One idea says that such monster black holes formed from the collapse of giant clouds of gas and dust. Another says that smaller black holes merged to form the supermassive ones. But neither process could form a giant black hole quickly enough to match what astronomers see.
The new idea says these early galaxies formed around clouds of dark matter. Dark matter produces no energy, but we see its gravitational pull on the “normal” matter around it. If there was enough dark matter, it could pull in huge amounts of normal matter in a short time. The combined matter then would collapse to form a supermassive black hole.
According to this idea, supermassive black holes would form quickly — even before their home galaxies could fully take shape. So the dark monsters at the hearts of galaxies could have formed under the influence of dark matter.