Astronomers have discovered a black hole that is growing faster than almost any ever seen before.
Using NASA’s Chandra X-ray Observatory, researchers found that this black hole is consuming matter at a rate more than twice what scientists thought was possible.
The finding may help explain how some of the universe’s earliest black holes grew so huge in such a short time after the Big Bang.
This black hole, known as RACS J0320-35, lies about 12.8 billion light-years from Earth.
That means astronomers are seeing it as it was only about 920 million years after the universe began.
Despite being so young, it already weighs about a billion times more than our Sun and is producing more X-rays than any other black hole observed during the universe’s first billion years.
The black hole powers a quasar, an object so bright that it can outshine entire galaxies. Quasars form when enormous amounts of gas swirl around a black hole and fall inward, creating dazzling amounts of energy.
But this particular quasar is unusual because its black hole appears to be growing at 2.4 times the so-called Eddington limit.
The Eddington limit is the theoretical speed limit for black hole growth. As matter falls toward a black hole, it heats up and releases powerful radiation, including X-rays and visible light.
That radiation pushes back on the incoming matter.
At a certain point, known as the Eddington limit, the radiation pressure should balance the pull of gravity, preventing more material from falling in any faster. Yet RACS J0320-35 seems to be breaking this rule.
Normally, astronomers think black holes in the early universe had to be born very large—perhaps tens of thousands of times the mass of the Sun—to grow into billion-solar-mass monsters so quickly.
But if this black hole really has been growing far above the Eddington limit, it might have started from a smaller, more ordinary seed, possibly the collapse of a single massive star less than a hundred times the Sun’s mass.
By studying the X-ray spectrum collected by Chandra, scientists were able to estimate the black hole’s growth rate, which could be between 300 and 3,000 Suns per year. Other data from optical and infrared telescopes support the idea that this black hole is gaining weight faster than expected.
Adding to the mystery, RACS J0320-35 also produces powerful jets of particles moving near the speed of light. Such jets are rare in quasars, and researchers wonder if the black hole’s extreme feeding rate might somehow be responsible for launching them.
“This one object is helping us chase down one of the biggest questions in astrophysics: how the very first black holes formed and grew,” said Thomas Connor of the Center for Astrophysics.
Source: NASA.
