Astronomers have used JWST to discover the oldest black hole in the universe, which challenges current theories of black hole growth and may affect the development of its host galaxy GN-z11. An international research team led by the University of Cambridge used the James Webb Space Telescope (JWST) to detect the black hole, which dates back to 400 million years after the Big Bang, or more than 13 billion years ago.
Today (January 17), the magazine Nature reported this result, and the lead author, Professor Roberto Maiolino, called it "a huge leap."
The fact that this incredibly massive black hole - millions of times the mass of our sun - existed so early in the universe challenges our assumptions about how black holes form and grow. Astronomers believe that the supermassive black holes found at the centers of galaxies such as the Milky Way grew to their current size over billions of years. But the size of the newly discovered black holes suggests they may have formed in other ways: They may have been "born large," or they may be devouring matter five times faster than thought.
According to the Standard Model, supermassive black holes form from the remnants of dead stars, which may collapse to create a black hole with a mass of about a hundred times the sun. If it grows as expected, the newly discovered black hole would take about 1 billion years to grow to its observed size. However, when this black hole was detected, the universe was less than a billion years old.
"It's still too early to see such massive black holes in the universe, so we have to think about other ways they might have formed," said Majorino, from the Cavendish Laboratory and the Kavli Institute of Cosmology at the University of Cambridge. "Very early galaxies are extremely gas-rich, so they are like a cafeteria for black holes."
Like all black holes, this young black hole is devouring material from its host galaxy to fuel its growth. However, we found that this ancient black hole devoured matter much more vigorously than its later siblings.
This young host galaxy is called GN-z11, and it has such an energetic black hole at its center. Black holes cannot be directly observed and can only be detected through the clues of the vortex accretion disk formed near the edge of the black hole. The gas in the accretion disk becomes extremely hot and begins to glow and radiate energy in the ultraviolet range. Astronomers use this intense light to detect black holes.
GN-z11 is a compact galaxy, about a hundred times smaller than the Milky Way, but a black hole is likely to harm its development. When a black hole swallows too much gas, it pushes the gas away like a super-fast wind. This "wind" would halt the star formation process, slowly killing the galaxy, but it would also kill the black hole itself, since it would also cut off the black hole's source of "food."
Majorino said the huge leap JWST has brought makes this the most exciting time in his career. He said: "This is a new era: a huge leap in sensitivity, especially in the infrared, which is like going from Galilean to modern telescopes overnight. Before the Webb telescope came into use, I had thought that maybe the universe would be less interesting if we went beyond what the Hubble Space Telescope could see. But that is not the case at all: the universe has been generously showing us everything it has to offer, and this is just the beginning."
JWST's sensitivity means that older black holes may be discovered in the coming months and years. Majorino and his team hope to use future observations from JWST to try to find smaller black hole "seeds," which might help them unravel the different ways black holes might form: whether they start out large, or grow rapidly.
Compiled source: ScitechDaily