The “James Webb” telescope turns cosmology upside down: Massive galaxies in the early universe cannot be explained with current models.
State College – The galaxies that formed in the universe just after the Big Bang should be small. At least that is what astrophysics expects. But now images from the new James Webb Space Telescope (JWST) from the space organizations Nasa, ESA and CSA seem to be turning this understanding of the universe on its head. A research team has discovered six massive galaxies in the early Universe in the images.
The research group is surprised by their discovery: “These objects are much more massive than expected,” explains Joel Leja from the Pennsylvania State University in State College in a statement. Leja is part of the research team that analyzed the galaxy image. The specialist work for this was in the journal Nature published. “We expected to find only tiny, young baby galaxies at this point, but we have discovered galaxies as mature as our own in what was once thought to be the dawn of the universe,” reports the astrophysicist Leja in one communication.
James Webb Space Telescope looks almost to the Big Bang
Leja’s international research team found the galaxies some 500 to 700 million years after the Big Bang – in cosmic dimensions that is almost immediately after the Big Bang. The James Webb Space Telescope enables researchers with its infrared instruments to detect light emanating from the oldest stars and galaxies. In this way, researchers can look about 13.5 billion years into the past – up to just before the Big Bang, which according to current models happened about 13.8 billion years ago.
The research team is still not entirely sure that they have actually discovered ancient giant galaxies, because the galaxies can only be seen as small reddish dots on the JWST images. “This is our first look so far back, so it’s important that we keep an open mind about what we’re seeing,” Leja said. While the data suggested they are likely galaxies, the researcher also thinks it’s possible some of these objects could turn out to be eclipsed supermassive black holes.
Giant galaxies contradict cosmological models
“Independently, the amount of mass we have discovered means that the known mass of stars in this period of our Universe is up to 100 times greater than previously thought. Even if we halve the sample, it’s still an amazing change,” explains Leja. The astrophysicist’s discovery “challenges what many of us thought was scientifically proven.” “We have informally referred to these objects as ‘universe breakers’ – and they have lived up to their name so far.”
According to the research group, the galaxies are so massive that they disagree with 99 percent of all cosmological models. To explain the large mass, one would have to either rewrite the cosmological models or revise the scientific understanding of how galaxies formed in the early Universe. So far, cosmology has assumed that galaxies start out as small clouds of stars and dust and gradually grow larger.
A very deep look into the early universe reveals amazing things
“We looked into the very early universe for the first time and had no idea what we would find,” says Leja. “It turns out that we found something so unexpected that it actually poses a problem for science.” His colleague Ivo Labbé, lead author of the study, recalls working with the recordings: “I run the analysis software and she spits out two numbers: distance 13.1 billion light-years, mass 100 billion stars, and I almost spit out my coffee. We have just discovered the impossible. Impossibly early, impossibly massive galaxies.”
One way to find out whether these are really very old galaxies would be to take spectra of the individual objects. This would allow the researchers to determine the actual distances and also find out what the galaxies are made of. With the help of this data, the scientists could also determine how massive the galaxies actually are. “A spectrum will tell us immediately whether these things are real or not,” explains Leja. (tab)