Beautifully named EGS-23205 and EGS-24268, these two galaxies would have appeared 11 billion years ago, while the current age of the Universe is estimated at 13.8 billion years.
The discovery of these galaxies of the same type as our Milky Way at such an early stage in the evolution of the Universe has surprised the authors of this work, the details of which will be published shortly in Astrophysical Journal Letters (new window). It challenges the generally accepted theory of the evolution of galaxies since the Big Bang.
The Milky Way is a barred spiral galaxy. Two of its neighbors, the Magellanic Clouds, appear in this composite image.
Photo: NASA/Nina McCurdy/Nick Risinger
Even more precision
Before the TSJW was deployed, Hubble Space Telescope images had never been able to observe barred spiral galaxies so shortly after the Big Bang.
In a Hubble image, the galaxy EGS-23205 takes the form of a disk-shaped blob, but in one by James Webb taken last summer, it takes the precise shape of a beautiful spiral galaxy with a star bar, explains in a press release Professor of Astronomy Shardha Jogee of the University of Texas at Austin.
Thanks to TSJW, four other 8-million-year-old galaxies have also been observed.
Montage of images taken with the James Webb Telescope showing six examples of barred galaxies.
Photo: NASA/CEERS/University of Texas at Austin
Galactic Landmarks
- A galaxy is a collection of stars, dust, gas, and dark matter held together by gravity.
- A supermassive black hole is at the center of the vast majority of galaxies, which come in a variety of sizes (from 2,000 to over 500,000 light-years across) and shapes (spirals, ellipses, and irregularities).
- They come together in the form of galaxy clusters and superclusters.
- Our Sun and its planetary system are in the Milky Way amidst 100 to 400 billion other stars orbiting the black hole Sagittarius A*.
- There would be no fewer than 2000 billion galaxies in the observable universe.
Star forming bars
Starbars are elongated star-filled structures that extend from the center of some galaxies to the various outer disks. These bars play an important role in the evolution of galaxies as they channel gas toward the central regions, which encourages star formation.
As we need to transport raw materials from ports to factories that produce new products, a rod transports gas to the central galactic region where it is rapidly being converted into new stars at a rate typically 10 to 100 times faster than in the Rest of the galaxy, the Pre Jogee adds.
In addition, bars also contribute to the growth of supermassive black holes at the centers of galaxies.
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A scenario to review
The discovery of bars at such early times in the evolution of the universe confounds cosmic evolution scenarios.
“Models of galaxy evolution now have a new ability where bars accelerate the production of new stars in early epochs. »
— A quote from Shardha Jogee, University of Texas at Austin
Furthermore, the mere existence of these early bars challenges current theoretical models of the physics of galaxies, which need to be redesigned to correctly predict their abundance in the Universe.
The Pre Jogee team also wants to test various new models in the coming months.