An international team of astronomers has announced that they have discovered what would be the oldest galaxy found to date. The candidate galaxy to hold the title of oldest observed has been named GLASS-z13 and is estimated to be 13.5 billion years old, about 300 million years after the big bang. It could be about 33,000 million light years from us.
The discovery has been announced by an international team of astrophysicists through an article published in the ArXiv repository and whose authorship is headed by Rohan Naidu, from the Harvard & Smithsonian Center for Astrophysics. Therefore, it is still a work that has not been peer-reviewed, although it has generated great interest from the scientific community.
The discovery was made through the first data published by the JWST. Specifically thanks to the NIRcam instrument, the main receiver of infrared images of the orbiting telescope.
🚨 JWST has potentially smashed records, spotting a galaxy which existed when the universe was a mere 300 million years old! The light from GLASS-z13 took 13.4 billion years to hit us, but the distance between us is now 33 billion light years due to the expansion of the universe! pic.twitter.com/5AcOBwHuO1
— Dr. James O’Donoghue (@physicsJ) July 20, 2022
This discovery is more than just a curiosity, and can tell us a lot about the period in which the first galaxies formed. Among other things because although GLASS-z13 is the oldest galaxy observed, it is not the only one of its characteristics. The galaxy is accompanied by another, GLASS-z11, a little less old at 13.4 billion years.
These “ages” refer to the fact that the galaxies existed at the time, although we cannot know how old they were at the time they emitted the light beams that reached Webb’s instruments.
Small and primitive.
Galaxies meet some of the characteristics that would be expected of them. It is estimated, for example, that their sizes represent a small fraction of that of the Milky Way. GLASS-z13 is approximately 1,600 light-years across, with a mass of 1 billion Suns. GLASS-z11, somewhat larger, would reach a diameter of 2,300 light-years.
These galaxies also have simple structures, unlike galaxies like ours that have defined regions such as spiral arms that extend from the galactic center to its periphery.
So far so normal, but the finding of GLASS-z13 has also brought surprises: it is noticeably brighter than experts would expect for such a primitive galaxy. This implies that, if the observations are confirmed, it would be necessary to review the knowledge we have about how they were formed and the speed at which they were formed.
So far so normal, but the finding of GLASS-z13 has also brought surprises: it is noticeably brighter than experts would expect for such a primitive galaxy. This means that, if the observations are confirmed, it would be necessary to review the knowledge we have about how they were formed and the speed at which they were formed. Perhaps it could even imply that galaxies began to form earlier than we thought.
The record so far.
GLASS-z13 is older than what was previously the oldest galaxy observed: GN-Z11. At 13.4 billion years old, this galaxy is about the same age as GLASS-z11. GN-Z11 was discovered in 2016 by the Hubble telescope.
The combined sample of these three galaxies can help astronomers better understand what the first 500 million years after the big bang were like, how the first galaxies formed, and at what rate they might have started to emerge.
Work to do.
The obvious first step now for Naidu and his team is peer review of the article and publication in a journal (although the community is optimistic). In the meantime, keep collecting data. Specifically, through a spectroscopic analysis, which allows knowing more precisely the distance at which it is located.
Just a week after the publication of the first images and data from the JWST, the interesting findings begin. All this despite the numerous problems that the device has had to face in recent weeks. We can only wait for the next surprise (hopefully positive) that this multi-million dollar tool has in store for us.
Image | POT
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