by The James Webb Space Telescope (JWST) has seen light from the stars around some of the earliest supermassive black holes in the universe – black holes seen as they were less than a billion years after the Big Bang.
The observations made by a team from the Massachusetts Institute of Technology (MIT) address the question of how these cosmic titans that sit in the heart of galaxies grew into huge masses, equivalent to millions of suns (sometimes even billions). Specifically, how did they grow so quickly? The results could also answer the question: What came first, the galaxy or the supermassive black hole?
The supermassive black holes observed by the MIT team are inexorably feeding the surrounding matter, generating enormous tidal forces in a disk of matter called an accretion disk, causing the disk itself to burn. This state of life powers objects called quasars, which sit at the heart of active galaxies. Quasars are among the most luminous objects in the cosmos, some of which are so bright that they outshine the combined light of all the stars in the galaxies around them.
Supermassive black holes are also surrounded by mystery – especially when they were spotted earlier than 1 billion years in the universe’s 13.8 billion year history. That’s because the continuous merging process of black holes, by which scientists think supermassive black holes grow over time, should take billions of years to proceed. So how could these huge vacancies exist about 1 billion years after the Big Bang?
Well, one suggestion is that they got a head start, coming from so-called “heavy seed” black holes.
Related: A new view of the supermassive black hole at the heart of the Milky Way suggests a disturbing hidden element
By using the JWST to observe faint light coming from the stars in the host galaxies of six ancient quasars, the MIT team has, for the first time, gathered evidence that supermassive black holes did indeed grow in the early universe from heavy seeds.
“These black holes are billions of times more massive than the sun, at a time when the universe is still in its infancy,” Anna-Christina Eilers, a team member and assistant professor of physics at MIT, said in a statement. “Our results suggest that supermassive black holes may have reached their mass early in the universe before their host galaxies, and that the initial black hole seeds may have been larger than they are today.”
What came first? A black hole or a galaxy?
Discovered in the 1960s, the intense brightness of quasars was originally believed to originate from a single star-like point. This led to the name “quasar,” which is a portmanteau of the term “quasi-stellar” object. However, researchers soon discovered that quasars are actually caused by massive amounts of material accreting to supermassive black holes in the hearts of galaxies.
However, these objects are also surrounded by stars, which are much fainter and harder to see. That is because this starlight is washed out by the brightest light of the orbiting quasar stars. So, separating the light from the quasars and the light from the stars around them is no big deal, like seeing the light of fireflies sitting on a lighthouse lamp a mile away.
The JWST’s ability to look further back in time than any previous telescope, combined with its high sensitivity and resolution, makes this challenge less daunting, however. Therefore, the MIT team managed to look at the light that has been traveling to Earth for about 13 billion years from six quasars in ancient galaxies.
“The quasar dwarfs its host galaxy by orders of magnitude. And previous images were not sharp enough to distinguish the appearance of the host galaxy and all its stars,” team member Minghao Yue, a postdoc at the Kavli Institute for Astrophysics Research and Space of MIT, said. “Now, for the first time, we can reveal the light from these stars by very carefully modeling the much sharper JWST images of these quasars.”
The JWST data included measurements of the light emissions of each of the six quasars over a range of wavelengths. This information was then fed into a computer model that determined how much of this light could be attributed to a compact point source — the accretion disk around the black hole — and how much could be attributed to a more distant source. diffuse — the stars scattered throughout the galaxy. .
By splitting the light into two sources, the team was able to determine the mass of both elements of these galaxies. This indicated that supermassive black holes have masses equal to about 10% of the mass of the stars around them.
While this may seem like a huge imbalance in favor of the stars, consider how, in modern galaxies, central supermassive black holes have only 0.1% the mass of the stars in their surrounding galaxies.
“This tells us what grows first: Does the black hole grow first, and then the galaxy succeeds? Or does the galaxy and its stars grow first, and is the largest and dominates the growth of the black hole?” Eilers said. “We see that black holes in the early universe appear to be growing faster than their host galaxies.
“That’s tentative evidence that the initial black hole seeds may have been larger back then.”
Related Stories
— James Webb Space Telescope finds ‘extremely red’ supermassive black hole growing early in the universe
— The brightest quasar ever seen is powered by the black hole that eats ‘a sun a day’
—Black hole-like ‘gravastars’ could be stacked like Russian tea dolls
“After the universe came into being, there were seed black holes that ate matter and grew in a very short time. One of the big questions is understanding how the black holes could That monster grew so big, so fast,” said Yue. “There must have been some mechanism to get a black hole out earlier than its host galaxy in those first billion years.
“It’s kind of the first evidence we’re seeing of this, which is exciting.”
The team’s findings are published in the Astrophysical Journal.
