“Sleeping” supermassive black hole found in early universe, scientists say

An international team of astronomers has discovered a dormant supermassive black hole in the early universe using the James Webb Space Telescope, dating back to just 800 million years after the Big Bang.

The black hole, with a mass 400 million times that of our Sun and comprising about 40% of its galaxy’s total mass, is one of the most massive ever found from this early period of the universe.

However, it is consuming gas at only about 1% of its theoretical maximum rate, making it essentially inactive.

“This discovery challenges our existing models of black hole growth”, said Professor Roberto Maiolino from Cambridge University’s Kavli Institute for Cosmology, one of the study’s authors. “Black holes might either be born large or go through periods of hyperactivity followed by long dormant phases”.

The findings, published in Nature, suggest that supermassive black holes may exceed their theoretical growth limit (the Eddington limit) for brief periods of intense activity, followed by extended periods of dormancy.

Computer simulations indicate these black holes likely feed for five to ten million years before entering dormant phases lasting around 100 million years.

The black hole’s detection, despite its dormant state, was possible due to its enormous size. Researchers note that such “sleeping” black holes are typically much harder to detect as they emit less light.

The discovery raises new questions about black hole formation in the early universe, challenging conventional models that suggest they form from the remnants of dead stars and accumulate matter at a predictable rate.