Hidden within the cosmos, a corner of space filled with primordial galaxies has been revealed by the James Webb telescope. These are the first galaxies in the universe, born after the Big Bang, and they look entirely different from the galaxies we have observed since.
Unveiling the Ancient Past
Just days after its official launch into space exploration, the James Webb telescope has transported astronomers back in time to the existence of the universe’s first galaxies, which were previously hidden from human observation.
“Everything is new. The James Webb telescope is revealing to us an incredibly unique and abundant universe beyond our imagination,” according to Professor Tommaso Treu, the principal investigator of the James Webb program at the University of California, Los Angeles.
The professor admits that once again, the universe has surprised everyone. “The early galaxies are highly distinctive in many ways,” he said. Based on the data from James Webb, astronomers worldwide have published impressive reports.
A Special Pair of Galaxies
The Astrophysical Journal Letters recently published two research papers from the National Institute for Astrophysics in Rome, Italy, and the Harvard-Smithsonian Center for Astrophysics and the Massachusetts Institute of Technology (MIT) in the United States.
These are two papers presenting the discovery of two remarkable and prominent galaxies, calculated to have existed approximately 350 million years (named GLASS-z12) and 450 million years (unnamed) after the Big Bang. Astronomers were surprised by the excessive brightness emanating from these young galaxies.
Through the James Webb telescope, they detected a pair of galaxies producing stars at an astonishing rate. Furthermore, their appearance seemed to be compressed into a spherical or disk-like shape, significantly smaller in size compared to the Milky Way.
Portrait of the Oldest Known Galaxy to Date: GLASS-z12. NASA, ESA, CSA
GLASS-z12 is also the oldest known galaxy discovered to date. The previous record holder was GN-z11, which existed approximately 400 million years after the Big Bang and was found in 2016 thanks to the Hubble telescope and the Keck Observatory in Hawaii.
Paola Santini, one of the authors of the report from the Italian National Institute for Astrophysics in Rome, explained that the results obtained from these new observations have opened up a completely different chapter for the field of astronomy. “It’s like an archaeological excavation where you unexpectedly find a lost city. It’s truly mind-blowing,” she said.
The Swift End of the Dark Ages
Observations from the James Webb telescope have allowed astronomers to draw a surprising conclusion: the first galaxies likely began forming only about 100 million years after the Big Bang. “No one could have imagined that the dark age era (the period following the Big Bang until the first light) ended so soon,” said Professor Garth Illingworth of the University of California, Santa Cruz.
“At that time, the primordial universe we’ve just discovered was only 1/100th the age of the present,” the professor added. Currently, the universe is approximately 13.8 billion years old.
The next set of observations using spectroscopic techniques is expected to confirm the distances to these galaxies, as well as potentially reveal the rate of star formation and the density of the components that make up the early stars of the universe.