Scientists are taking a closer look at supermassive blackholes by simulating them on computers. They've examined how supermassive black holes and galaxies formed from collapsing gas clouds in the early universe.
In the past, researchers believed that supermassive black holes were first created after the collapse of the very first stars. But new work shows that this may not be true since these collapses would only lead to small black holes. Now, scientists are taking a closer look at what may have caused supermassive black holes to first form.
"The early universe was a dense, hot and uniform plasma," said Kentaro Nagamine, one of the researchers. "As it cooled, fluctuations in the mass distribution formed seeds around which matter could gather due to gravity."
In this latest study, the researchers simulated a situation that was new for supermassive black holes. They modeled supermassive black holes that were seeded by clouds of gas falling into potential wells that were created by dark matter. In order to accomplish this simulation, the researchers used "sink particles" in order to simplify the dynamics of large gas clouds.
"Although we have access to extremely powerful supercomputers at Osaka University's Cybermedia Center and the National Astronomical Observatory of Japan, we can't simulate every single gas particle," Nagamine said. "Instead, we model small spatial scales using sink particles, which grow as the surrounding gas evolves. This allows us to simulate much longer timescales than was previously possible."
So what did they find with the simulations? It turns out that most seed particles didn't grow very much. This is true except for one central seed, which grew to more than 2 million solar masses in just 2 million years, which is extremely fast, all things considered. This particular seed could be the start of a supermassive black hole, especially when considering that as gas spun and collapsed around the central seed, it formed two misaligned accretion discs.
The findings reveal a bit more about the formation of supermassive black holes. More specifically, they reveal how it wasn't the collapse of the first stars, but was another mechanism entirely that likely formed them.
The findings are published in the March 2016 journal Monthly Notices of the Royal Astronomical Society.
