A spiral galaxy of the same type as the Milky Way has been discovered at the edge of the universe by an international team of astronomers using data from the James Webb Space Telescope.
Specifically, Ceers-2112 is the most distant barred spiral galaxy discovered to date. In this type of galaxy, the spiral arms do not emerge from the center of the galaxy, but rather from a band of stars that crosses this center.
This discovery comes as a big surprise to astrophysicists, who had previously assumed that it took several billion years for galaxies to become sufficiently structured and ordered to develop bars.
They therefore estimated that this type of galaxy could not have formed until the universe had reached at least half its age, about 13.8 billion years.
The discovery of Ceers-2112 shows that this can happen much faster, perhaps even in less than a billion years.
“Our work shows that galaxies similar to the Milky Way existed 11.7 billion years ago, when the Universe was only 15% of its current age,” explains astronomer Luca Costantin from the Spanish Institute of Aerospace Engineering and lead author of the study Article published in the journal Nature (New Window) (in English).
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The Milky Way and the two Magellanic Clouds.
Photo: NASA/Nina McCurdy / Nick Risinger
Galactic landmarks
- A galaxy is a collection of stars, dust, gas and dark matter held together by gravity.
- There are four main categories, classified according to their shape and physical properties: spiral, elliptical, lenticular and irregular.
- Our sun and its planetary system are located in a barred spiral galaxy, the Milky Way, which consists of 100 to 400 billion other stars.
- There are no fewer than 2,000 billion galaxies in the observable universe.
To better understand our galaxy
By studying the structure of galaxies at different distances (corresponding to different ages of the universe), scientists are trying to reconstruct the evolution of our own Milky Way.
However, the vast majority of massive spiral galaxies in the nearby universe are excluded.
However, according to theoretical models, the physical conditions prevailing in the early universe did not favor the formation of bars in galaxies, since these bars must occur in spiral galaxies whose stars rotate in an orderly manner.
The discovery of ceers-2112 shows that galaxies in the early universe could be as ordered as the Milky Way, which is surprising, said astronomer Alexander de la Vega of the University of California, Riverside, who was involved in the work, in a statement.
Our theoretical models of galaxy formation and evolution must take into account the fact that some galaxies became stable enough to accommodate bars very early in the evolution of the universe.
You should know that galactic bars play an important role in the evolution of galaxies as they promote the mixing of elements that are essential for the formation of stars (like the Sun).
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The Webb Revolution
Current knowledge of primitive galaxies is based primarily on data obtained with the Hubble Space Telescope, but the extraordinary capabilities of the James Webb Space Telescope are sure to revolutionize our understanding of the distant universe.
With James Webb, for the first time we have the technology and instruments necessary to study the morphology of very distant galaxies in detail. This helps us understand how galaxies acquired the structures that characterize them today in order to understand the evolution of the universe.
The James Webb Telescope was launched on December 25, 2021 from French Guiana. Thanks to its huge primary mirror and four instruments that detect infrared signals, it is able to see further into the universe than any other telescope, allowing it to penetrate dust clouds.