A newly published research paper presented the discovery of six galaxies that are too young and too dense to be explained by previous theories about how the universe was formed. In the words of one scientist, “It’s bananas!”
According to astrophysicists, the universe came into existence 13.8 billion years ago as a result of the Big Bang, a theory that the universe expanded from an initial state of high density and temperature. According to this theory, the earliest galaxies did not form until 350 million years later. These galaxies were relatively small, containing perhaps 100 million stars. Our galaxy, dubbed the Milky Way, is relatively young and correspondingly larger, containing an estimated minimum of 100 billion stars.
But these theories are being challenged by the discovery of six new galaxies by researchers using the James Webb Space Telescope. The research, published in the Nature journal on Wednesday, reported that the newly discovered galaxies appeared 540-700 million years after the Big Bang but contain tens of billions of stars, if not more.
The largest of these systems is believed to have a collective mass about one trillion times greater than our sun, making it 10 times the mass of the Milky Way but 30 times as dense.
“Oh, they are radically different – truly bizarre creatures,” said astrophysicist Ivo Labbe of Swinburne University of Technology in Australia, lead author of the study. “If the Milky Way were a regular-sized average adult, say about five foot nine inches and 160 pounds, these would be 1-year-old babies weighing about the same but standing just under 3 inches (7 cm) tall. The early universe is a freak show.”
“Adding up the stars in those galaxies, it would exceed the total amount of mass available in the universe at that time,” said Prof. Labbe.
The vast size and complexity of these relatively young star systems defy previous theories about how galaxies are formed.
“It’s bananas,” said Erica Nelson, an assistant professor of astrophysics at the University of Colorado, Boulder, and a co-author of the paper, in a statement that accompanied its release. “You just don’t expect the early universe to be able to organize itself that quickly. These galaxies should not have had time to form.”
This seems to be the consensus of the scientists.
“This is an astounding discovery and unexpected. We thought that galaxies form over much longer periods of time,” said Penn State astrophysicist and study co-author Joel Leja. “No one expected to find these. These galaxy candidates are simply too evolved for our expectations. They seem to have evolved faster than allowed by our standard models.”
The scientists are still struggling to explain the incongruous discovery and more data is needed. The discovery was made last summer when the Webb Telescope was observing a piece of the sky near the Big Dipper. This piece of sky was previously observed by the Hubble Space Telescope which operates principally in the visible light spectrum. The new discovery was made using the more advanced Webb telescope, the largest optical telescope in space that was launched 13 months ago at a total cost of $10 billion and began sending images back to earth in July. The Webb Telescope operates in the infrared spectrum.
One alternative theory is that they are not galaxies but, rather, an alternate source of radiation, perhaps even supermassive black holes.
“The exciting part is that even if only some turn out to be massive galaxies, these things are so massive that they alone would upend our measurements of the total mass in stars at this time,” Leja said. “It would suggest 10 to 100 times more mass in stars existing at this epoch than expected and would imply that galaxies form way, way faster in the universe than anyone thought.”