James Webb Space Telescope suggests supermassive black holes grew from heavy cosmic 'seeds'

A James Webb Space Telescope image of the quasar J0148 and the supermassive balck hole at its heart
A James Webb Space Telescope image of the quasar J0148 and the supermassive balck hole at its heart (Image credit: NASA/Yue, et al)

The James Webb Space Telescope (JWST) has observed light from stars surrounding some of the earlier supermassive black holes in the universe — black holes seen as they were less than a billion years after the Big Bang. 

The observations conducted by a team from the Massachusetts Institute of Technology (MIT) addresses the question of how these cosmic titans that sit at the hearts of galaxies grew to tremendous masses, equivalent to millions (sometimes even billions) of suns. More specifically, how did they grow so rapidly? The findings could also answer the riddle: What came first, the galaxy or the supermassive black hole?

The supermassive black holes observed by the MIT team are insatiably feeding on surrounding material, generating immense tidal forces in a disk of matter called an accretion disk, thereby causing the disk itself to glow. This feeding situation powers objects called quasars, which sits at the hearts of active galaxies. Quasars are among the most luminous objects in the cosmos, with some so bright they outshine the combined light of every star in the galaxies around them.

Supermassive black holes are surrounded by mystery, too — especially when seen earlier than 1 billion years in the 13.8 billion-year history of the universe. That is because the continuous merger process of black holes, by which scientists think supermassive black holes grow over time, should take many billions of years to proceed. So, how could these giant voids exist only about 1 billion years after the Big Bang? 

Well, one suggestion is that they got a head start, forming from so-called "heavy seed" black holes.

Related: New view of the supermassive black hole at the heart of the Milky Way hints at an exciting hidden feature

By using the JWST to observe faint light coming from stars in the host galaxies of six ancient quasars, the MIT team has, for the first time, collected evidence that supermassive black holes in the early universe indeed grew 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, team member and assistant professor of physics at MIT, said in a statement. "Our results imply that in the early universe, supermassive black holes might have gained their mass before their host galaxies did, and the initial black hole seeds could have been more massive than today."

What came first? The black hole or its galaxy?

Discovered in the 1960s, the intense brightness of quasars was initially 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. Researchers soon found, however, that quasars are actually caused by vast amounts of matter getting accreted to supermassive black holes at the hearts of galaxies. 

However, these objects are also surrounded by stars, which are much fainter and more difficult to observe. That is because this stellar light is washed out by the brighter light of the quasar the stars orbit. Thus, separating out light from quasars and light from stars around them is no mean feat, akin to seeing the light of fireflies sitting on the lamp of a lighthouse around a mile away.

The JWST's ability to peer further back in time than any prior telescope, coupled with its high sensitivity and resolution, has made this challenge less daunting, however. Thus, the MIT team managed to observe light that has been traveling to Earth for around 13 billion years from six quasars in ancient galaxies.

"The quasar outshines its host galaxy by orders of magnitude. And previous images were not sharp enough to distinguish what the host galaxy with all its stars looks like," team member Minghao Yue, a postdoc at MIT's Kavli Institute for Astrophysics and Space Research, said. "Now, for the first time, we are able to reveal the light from these stars by very carefully modeling JWST's much sharper images of those quasars."

An illustration of a quasar at the heart of an active galaxy (Image credit: NASA/JPL–Caltech)

The JWST data included measurements of each of the six quasars' light emissions across a range of wavelengths. This information was then introduced to a computer model detailing how much of this light could be attributed to a compact point source — the accretion disk around the black hole — and how much can be attributed to a more diffuse source — the stars scattered around the galaxy. 

By splitting the light into two sources, the team was also able to infer the mass of both elements of these galaxies. This revealed that the supermassive black holes have masses equal to around 10% of the masses of the stars around them. 

While this might sound like a massive imbalance in favor of the stars, consider how in modern galaxies, central supermassive black holes have masses merely 0.1% that of the stars in their surrounding galaxies.

"This tells us something about what grows first: Is it the black hole that grows first, and then the galaxy catches up? Or is it the galaxy and its stars that first grow, and they dominate and regulate the black hole’s growth?" Eilers said. "We see that black holes in the early universe seem to be growing faster than their host galaxies. 

"That is tentative evidence that the initial black hole seeds could have been more massive back then."

"After the universe came into existence, there were seed black holes that then consumed material and grew in a very short time. One of the big questions is to understand how those monster black holes could grow so big, so fast," Yue concluded. "There must have been some mechanism to make a black hole gain their mass earlier than their host galaxy in those first billion years.

"It's kind of the first evidence we see for this, which is exciting."

The team's results are published in the Astrophysical Journal.

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Robert Lea
Senior Writer

Robert Lea is a science journalist in the U.K. whose articles have been published in Physics World, New Scientist, Astronomy Magazine, All About Space, Newsweek and ZME Science. He also writes about science communication for Elsevier and the European Journal of Physics. Rob holds a bachelor of science degree in physics and astronomy from the U.K.’s Open University. Follow him on Twitter @sciencef1rst.

  • skynr13
    The first stars were giant blue stars consisting only of hydrogen and within a few million years went Nova and always made a BH. So isn't it possible that these Quasars came from many of those combining to make one?
  • Jbwoy79
    skynr13 said:
    The first stars were giant blue stars consisting only of hydrogen and within a few million years went Nova and always made a BH. So isn't it possible that these Quasars came from many of those combining to make one?
    Any cosmic merger whether a star, neutron star or blackhole takes a tremendous amount of time to unfold. While it is certainly possible that due to a large number of supernovae events occurring that early black holes had a lot of gas to feed on..But even still to grow to such levels while starting as a single stellar blackhole is simply impossible.

    One thing that should be considered is that before reionization the entire universe was many magnitudes hotter and denser. This environment would have allowed much smaller objects to become black holes and even small fluctuations in density pressure would have allowed for event horizons to form. Likewise, once an event horizon had formed during these most early stages..the hot and dense surroundings would have been perfect for feeding these newborn BH’s.

    I think the best way to imagine it..is consider a black hole to be like a wet dry vac sucking up its surroundings. After reionization, black holes functioned like a wet-vac would if it were sucking up dust and moisture directly out of air. However, in the earliest stages when it was sufficiently hot and dense..Blackholes would work as if sticking the nozzle directly into water.
  • skynr13
    i agree with most everything you've said. But I think that what you say in your first paragraph is relating the first millions of years after the BB to now. I really believe that in these first millions of years, things where quite different in terms of star formation and BH creation. With many BH's small and large so close to each other that it didn't take long for them to condense to something very massive. And with the many huge Blue stars contributing to this BH gathering, SMBH's would have become commonplace quite quickly. My main problem with your description is the last sentence in the last two paragraphs contradict themselves, and is like how I see most scientists determinations about things nowadays.
  • Questioner
    The higher density of the early universe works for black holes, but heat/higher-temperatures I would think runs counter to that. To get hydrogen to pile up enough to build/ignite a star takes specifically cold hydrogen.
    I wonder if the early universe had some mechanism for cooling matter?
  • billslugg
    It is not understood how primordial hydrogen clouds could shed heat so fast and collapse quickly enough to account for the observed number of SMBHs as far back as Webb can see.
  • Unclear Engineer
    I do not see why the temperature of the hydrogen gas or plasma really matters with respect to collapse into a black hole. The plasma in the center of stars collapses when the fusion process gets too weak to stop it. The question if really just related to matter density distribution variations in the early universe. And, the Big Bang Theory has the universe starting at a density that would be a black hole to begin with. Actually far more dense than needed. So, why could this not have resulted in some black holes remaining from the postulated "inflation" not being as uniform as the BBT hypothesizes?

    The argument against density variations large enough to cause collapse into black holes seems to come from the interpretations of the Cosmic Microwave Background Radiation (TV noise). Maybe we aren't interpreting that correctly?
  • mdswartz
    My view is that the smbh'es were there before our big bang and survived our big bang, along with their galactic cores, but they were mostly stripped of stars. These galactic remnants became some of the drivers for very early galaxy formation and quasars shortly after our big bang. This is because big bangs are natural occurrences that happen from time to time, and they occur in the greater universe, via a pulverizing explosion of primordial matter from a single hot dark dense state. The primordial matter came from one of the only places in the universe that primordial matter exists, namely, a black hole, as there is no other source.

    What was there before our big bang? The universe. Where did the primordial matter come from? A black hole of roughly one big bang of mass. Why were there such big galaxies and quasars shortly after our big bang? Because their starting point was the well-established smbh'es and galactic remnants. Did space expand? No, primordial matter transitioned into regular matter and expanded into open spaces of the universe. Why does our section of the universe appear to be expanding at an increased rate? Because the force of the blast powered expansion of our section of the universe for the first 10 billion years or so, but as our section grew ever outward the force of the blast waned, and gravity from the rest of the universe has now become primary and acts to help pull our section apart in all directions, now faster than the force of the blast alone.
  • billslugg
    We know the state of the universe at t=780,000 years, it was a bright cloud of hydrogen. We can see it by looking at the CMBR. After that time the hydrogen gas was tranparent. The problem is that contraction of these gas clouds due to their own gravity results in an increase in temperature which causes them to stop contracting. Only when some BTUs are shed can they collapse further. The rate of cooling of large diffuse clouds of hydrogen in not known well. There are many constants to the equations we don't know well. There are many wavelengths given off by atomic and molecular hydrogen, those wavelengths each experience different opacities in trying to get out of the cloud. It's very complex and we don't understand it well. Our current equations have the clouds taking much longer than what we see out there. Unfortunately, at this stage of the universe there are no such clouds to examine close up, we have to look back in time 13 billion years. Need more data.
  • Questioner
    In mechanical refrigeration a sudden drop in pressure reduces the temperature.

    Could the instant of inflation have caused a sudden drop of temperature that opened the opportunity for cold matter condensation(s)?
  • mdswartz
    Black holes aren't infinitely hot, they only hold the heat of the trillions of stars they took in. But the temperature seems infinite because the primordial matter seems infinitely dense. But I'd guess upon transition to regular matter expanding into the open spaces of the greater universe, temperatures revert back to the temperatures of the stars before taken into the black holes, temperatures that support transition to atomic matter.