Just two weeks ago we received news of the oldest and most distant galaxy seen by human beings, but it may have been a short-lived record: An international team led by researchers from the University of Edinburgh has identified what could be the oldest and most distant galaxy distant observed to date.
A record to be confirmed.
The new oldest galaxy candidate observed has the name CEERS-93316 and is located about 35,000 million light years from us. At the time it emitted the light that we observe today, we observe from it that only 235 million years had passed since the Big Bang. That is, the galaxy is more than 13.5 billion years old.
This galaxy has been detected thanks to the first batch of data published by the James Webb Space Telescope (JWST) team, which was made available to researchers around the world at the same time that the first images captured by this telescope.
The team has reported the discovery through a draft that has been published in the ArXiv repository waiting to be peer reviewed and published in a scientific journal. In the meantime, the team continues to work to obtain more information about the galaxy to confirm the first results. These analyzes will include a complete spectrographic study of the object.
The importance of colour.
Spectrographic analysis is important. The galaxy once emitted visible light, but due to its long journey through space and time, it shifted towards the infrared until it became invisible to the human eye. But not to Webb’s eye, a telescope designed precisely to take images at these wavelengths.
Preliminary analyzes tell us, yes, of a galaxy of a blue color, the color that predominates among young galaxies since stars of this color predominate in them, which shine with great intensity but fade quickly, leaving room for those of reddish tones, longer.
“[Es] quite blue, suggesting a young stellar population. But it’s not blue enough for a galaxy made of metal-free stars.” By metal-free stars, Callum Donnan, a researcher whose name heads the article’s publication, refers to stars composed mainly of helium and hydrogen (and small amounts of lithium), the first elements to appear after the Big Bang. The rest of the elements would have arisen from these original stars.
A couple of weeks ago GLASS-z13 became the oldest and most distant galaxy to be detected. It was also the first batch of JWST data that identified this galaxy as one of the oldest and most distant. Located about 35,000 million light years from us, its image would have been emitted 13,500 million years ago, when the Universe as we know it was “only” about 500 million years old. He accompanied her on this discovery GLASS-z11, about 13.4 billion years old.
A few days later, Maisie’s Galaxy was identified, which would have existed some 280 million years after the Big Bang. The list of ancient galaxies is expanding.
These discoveries are great news since to understand the first few hundred million years of our universe, the time when galaxies began to form, we need to have a good sample of examples. We have gone from having a single example of this to having at least five. And all this a few weeks after NASA published the first batch of data from the famous telescope.
Understanding these galaxies will help us solve certain puzzles that these same discoveries have generated. In the case of GLASS-z13, the surprise came from the intensity with which the object shone, while in this case the fascinating thing may be its less blue color than would be expected.
In some respects these galaxies do agree with our understanding of cosmology. For example, the fact that they have the appearance of small formless masses, that is, they lack the complex structures that characterize galaxies like ours, presumably formed by billions of years of interactions between smaller and simpler galaxies.
Little vocation of permanence.
Everything seems to indicate that, with various teams analyzing the JWST data throughout the world, this record will not last long either. The telescope is a time machine and the first of the blocks of information that the Webb will give us, active for only a few months, is still being analyzed.
“We’re using a telescope that was designed for just this kind of thing, and it’s fascinating. It is allowing us to look back at the formation of the first stars and galaxies more than 13.5 billion years ago. Without a doubt, this is just the beginning of the many important observations that will be made with this incredible instrument in the coming weeks, months and years,” explained Donnan.
Image | University of Edinburgh; NASA, ESA