“Most early galaxies are expected to appear small and messy.”
rebel galaxy
Astronomers peering into the farthest reaches of our universe have made the “puzzling” discovery of the most distant rotating disk galaxy ever observed. And it looks a lot like ours, if not more eerily.
The structure, called REBELS-25, was revealed in detail using the Atacama Large Millimeter/Submillimeter Array (ALMA), as detailed in a study accepted for publication in an academic journal. Monthly Notices of the Royal Astronomical Society.
What really caught the researchers off guard was the galaxy’s unusually smooth and orderly structure, which scientists suggest requires billions of years’ worth of evolutionary changes.
“Our understanding of galaxy formation predicts that most early galaxies appear small and messy,” co-author Jacqueline Hodge, an astronomer at Leiden University, said in a statement.
What makes REBELS-25 stand out is that its origins date back 700 million years to when the universe was only 5 percent of its current age (13.7 billion years). This is despite the fact that REBELS-25 bears a striking resemblance to the Milky Way, which is slightly younger than the Universe (13.6 billion years old).
In other words, we thought it took 13.6 billion years to look as smooth as we do, but in reality, it only took 700 million years, as REBELS-25 actually proves. No.
“Seeing galaxies so similar to our own Milky Way and with strong rotational dominance adds to our understanding of how galaxies in the early universe evolved into the ordered galaxies of today’s universe. It raises questions,” explained first author Lucy, a PhD student at Leiden University. Roland.
spiral arms
Thanks to ALMA’s extremely high resolution, astronomers were able to understand REBELS-25’s unusually ordered structure and motion. This evidence also suggests that this galaxy has spiral arms and an elongated central bar, much like the Milky Way.
“Finding further evidence of a more evolved structure would be an exciting discovery, as this would be the most distant galaxy in which such a structure has been observed to date,” Roland said.
The research team now hopes to take a closer look, perhaps with the help of NASA’s James Webb Space Telescope, which could change our current understanding of how galaxies evolve over billions of years. There is a possibility that it will shake up even more.
“In particular, continued observations of other REBELS galaxies by ALMA will enable robust kinematic modeling of additional rotating disk candidates,” the researchers wrote in their paper.
Learn more about ancient galaxies: Scientists discover giant black hole that could destroy galaxies
