James Webb Telescope Unveils Sleeping Monster in the Early Universe.
Astronomers, using the James Webb Space Telescope, have made a groundbreaking discovery: a giant dormant black hole from the early universe, only 800 million years after the Big Bang. This black hole, with a mass 400 million times that of our Sun, is among the largest ever observed from that period. Despite its enormous size, it exhibits a surprisingly low accretion rate, effectively making it dormant.
The black hole is so massive that it constitutes roughly 40% of its host galaxy’s mass, a stark contrast to black holes in the modern universe, which typically make up only 0.1% of their galaxy’s mass. Its low growth rate—about 100 times below the theoretical limit—raises important questions about black hole growth models.
An international team of astronomers, led by the University of Cambridge, conducted this research, finding that black holes may experience short bursts of rapid growth followed by long periods of dormancy. This particular black hole is thought to have gone through such a cycle, accumulating its mass in brief spurts and then "sleeping" for millions of years.
The discovery challenges current models of black hole formation, which suggest black holes form from the collapse of stars and grow by accreting matter at a specific limit, known as the Eddington limit. However, this massive black hole’s existence at such an early stage suggests that black holes might either form much larger than expected or grow in bursts of activity.
The team's simulations suggest that black holes like this one could exceed the Eddington limit for short periods, allowing rapid growth followed by long periods of inactivity. This discovery sheds light on the nature of black holes in the early universe, hinting that most black holes might spend the majority of their time in a dormant state, potentially leading to the detection of many more such objects in the future.
