How Are Supermassive Black Holes Formed?

BEACON TRANSCRIPT – Researchers from Dublin City University, Georgia Tech, Columbia University, and the University of Helsinki put up a study that strengthens the theory on the formation of supermassive black holes. They studied two black holes that formed 800 million years after the Big Bang, which means 13.8 billion years ago.

Researchers use computer simulations to show the formation process of a black hole. Black holes grow rapidly in the center of the galaxy that hosts them only if another galaxy nearby emits radiation. The radiation is enough only if it disables the host galaxy and it can no longer form stars.

Thus, the disabled galaxy continuously grows until it collapses. This is the moment when the black hole is formed. It continues growing as it absorbs the remaining gas in the galaxy, and then dying stars, dust, or even other smaller black holes. This is how it becomes supermassive.

Supermassive black holes are created differently

Zoltan Haiman, an astronomy professor at Columbia University, explained how quick is this process when compared to the age of the universe.

“The collapse of the galaxy and the formation of a million-solar-mass black hole takes 100,000 years – a blip in cosmic time. A few hundred-million years later, it has grown into a billion-solar-mass supermassive black hole. This is much faster than we expected.”

Soon after the formation of the universe, stars and galaxies formed from molecular hydrogen. Such an environment wouldn’t have allowed for the formation of supermassive black holes, as the stars were created far enough to escape being absorbed. Thus, the scientists had to come up with hypotheses to explain the formation of supermassive black holes.

Computer simulation of black hole formation

Haiman and his team of researchers developed a study in 2008 that hypothesized that radiation can split the hydrogen molecules. If a galaxy is massive enough to emit strong radiation, molecular hydrogen can be split into atomic hydrogen and stars can be absorbed.

This study, published in the journal Nature Astronomy, also includes a software model of the formation process. The researchers also considered the effects on the process of chemistry, radiation, gravity, and fluid dynamics. They discovered that the nearby galaxy can be smaller than they had previously thought.

The researchers wait for NASA’s James Webb Space Telescope to go online so that they can test their hypothesis. If they find it true, they will offer an explanation to a process that has been on the mind of scientists for decades – the formation of supermassive black holes.
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