The high-definition infrared image taken by NASA’s Webb Space Telescope shows stars springing up like mushrooms after a rain. (NASA/ESA/CSA)
[The Epoch Times, March 15, 2024](Epoch Times reporter Chen Juncun reported) Astronomers used NASA’s James Webb Space Telescope to observe the largest object in the early universe The galaxy is growing much faster than originally expected. This could help rewrite astronomers’ understanding of galaxy formation and evolution and revise existing models of the universe.
The University of Melbourne in Australia stated in a press release on March 12 that a research team involving astronomers from the school used the Webb Space Telescope to observe primitive galaxies 500 million years after the Big Bang.
Scientists believe that the universe was born after the Big Bang 13.8 billion years ago and has a history of 13.8 billion years.
The team observed the universe in its infancy. They found that galaxies during that period were larger and more mature than previously expected, helping to rewrite their understanding of galaxy formation and evolution.
The team said they recently conducted unprecedented detailed observations of the galaxy Gz9p3 in the early universe. Gz9p3 appeared as a point of light on the Hubble Space Telescope a few years ago. The Webb Space Telescope, which has relatively advanced observation capabilities, allowed astronomers to observe the universe 510 million years after its birth.
The Webb Space Telescope is the largest and most powerful space telescope ever built. (NASA)
The team found that Gz9p3 was larger and more mature than they expected for the early universe. It already contains billions of stars and is by far the largest object known in the early universe, 10 times larger than any other galaxy at that time.
These observations suggest that for Gz9p3 to reach such a large size, its star must have grown much faster and more efficiently than previously thought.
One of the most distant merging galaxies in the early universe
Gz9p3 was not only the largest galaxy in the early universe, it was also one of the most distant merged galaxies in the early universe. Images taken by the Webb Space Telescope show that Gz9p3 shows a pattern that usually occurs when two galaxies merge, but its merger is not over yet.
When two massive objects like this merge, they throw away some matter in the process. This material informed astronomers that Gz9p3 is one of the most distant merging galaxies.
Z9p3 was the largest galaxy 500 million years after the birth of the universe, and it was also the brightest galaxy in the process of merging. The image on the left shows its central area with two cores. (University of Melbourne)
Using the Webb Space Telescope, astronomers can further examine the spectrum of Gz9p3 to learn about the stellar composition within the galaxy. Such spectroscopy is very detailed and allows them to see the signatures of these ancient stars.
Specific elements detected in the spectrum, including silicon, carbon and iron, showed that such an ancient population of stars must have existed to fill the galaxy with large amounts of chemicals.
Observations of Gz9p3 show that in the early days of the universe, galaxies were able to accumulate mass quickly through mergers, and their star formation efficiency was higher than expected.
The team says observations of Gz9p3 and other galaxies via the Webb Space Telescope are allowing astronomers to adjust models of the early universe.
“Our cosmology is not necessarily wrong, but our understanding of how quickly galaxies formed may be wrong because they are more massive than we believed,” said researcher Kit Boyett.
He said that as more and more galaxies are observed, astronomers studying the early universe are moving from the exploration stage to the stage where there are enough samples to start building and revising new models.
The above research results were published in the journal Nature Astronomy on March 7.
Editor in charge: Ye Ziwei#
