JWST has allowed astronomers to peer further into the past than any other infrared or optical telescope. 300 million years After the Big Bang.
We had hoped that the infrared telescope would tell us more about the formation of galaxies and shed light on the mystery of how supermassive black holes become so huge, but looking further back in time revealed some surprising facts.
One surprise is the tiny bright red dots of light. Scattered throughout The early universe, about 600 to 800 million years after its birth. First detected and analyzedAt the time, astronomers thought they might be giant galaxies, but this was at odds with how cosmological models predict that galaxies form as tiny clouds of dust and stars and grow over eons.
“The discovery that the formation of massive galaxies began very early in the history of the universe overturns what many of us thought was established science,” said Joel Reja, assistant professor of astronomy and astrophysics at Pennsylvania State University. statement Following early observations, we’ve informally dubbed these objects “space disruptors,” and so far they seem to be living up to the name.
Naturally, seeing an object that could potentially upend models of galaxy formation, the team wanted to be sure what it was they were looking at, so they set out to take these spectral images. Galaxy To learn more about the distance to the galaxy, its composition, and its actual mass, the researchers analyzed the objects and discovered that they are quite strange in many ways.
First, even though the galaxy is only 600 to 800 million years old, it appears to be chock-full of ancient stars that are hundreds of millions of years old. In addition to the oddity of its formation, this meant that the team was looking for the oldest starlight signatures ever found.
“These early galaxies would have been incredibly dense with stars. They must have formed in ways we’ve never seen, under conditions we’ll never see, and at times we’ll never see,” Reja said. statement Following the latest research, he added, “And for some reason, the universe stopped making objects like these after just a few billion years. They’re unique to the early universe.”
But there are still mysteries to be solved: The team estimates that at the center of the galaxy lies a staggeringly huge supermassive black hole, between 100 and 1,000 times the mass of the Sun. Sagittarius A* It is located in the center of the Milky Way. It is too large for the surrounding galaxies. If the galaxy were compressed to the size of the Milky Way, milky wayThe nearest star lies just outside our solar system, and the supermassive black hole at its centre is just 26 light-years from Earth and is visible as a giant pillar of light, the team said.
“Usually supermassive black holes are paired with galaxies,” Reja added. “They grow together and go through all of the major experiences of life together. But here we have a fully formed, adult black hole existing inside what should be a baby galaxy. This doesn’t make much sense, because these are supposed to grow together, or at least that’s what we thought.”
Supermassive black holes found in the nearer (more recent) universe are, as the name suggests, quite large. Cosmologists have been trying to understand how these supermassive black holes, found at the center of most universes, get to be.Not all) This is how galaxies grew to such large sizes.
Numerous theoryinclude merger Black holes FeedingThese early black holes and others Discovered by JWSTis larger than these ideas can explain, and appears to be much larger than cosmologists expected compared to the surrounding galaxy.
One idea that is perhaps becoming more favorable given recent observations is that of a “direct collapse” or “massive seed” black hole. Normally, to get a stellar-mass black hole (for the current age of the universe), a star collapses. In the case of a massive seed black hole, a supermassive black hole starts out with a mass of about 10,000 to 100,000 times that of the Sun, Direct gravitational collapse It has no intermediate stellar phase and is composed of a huge cloud of gas.
There are several reasons why this scenario seems unlikely: The gas cloud needs to collapse without fragmenting or clumping as it collapses, and astronomers suggest that heating the cloud could prevent this. Young stars near you If gas clouds were moving at supersonic speeds in “streams” in gas disks before the formation of the Galaxy, or in the early universe, they could grow for a longer period of time before gravity started to collapse the clouds into seed black holes.
At the moment it is difficult to distinguish the exact masses of the supermassive black holes at the centers of these galaxies from the surrounding stars. Further observations are planned to take spectra for longer periods of time to get a more precise picture.
“It’s very confusing,” Reja added. “You can force it into our current cosmic models, but only if you assume there was some exotic, unusually rapid formation at the beginning of time. This is without a doubt the strangest and most interesting collection of objects I’ve seen in my career so far.”
The latest research Astrophysical Journal Letters.
