Just a week after its first images were shown to the world, a scientist analyzing the data said Wednesday that the James Webb Space Telescope may have found a galaxy that existed 13.5 billion years ago.
Known as GLASS-z13, the galaxy’s history stretches back 300 million years from Earth. Big BangThat’s about 100 million years ahead of anything previously described, Rohan Naidu of the Harvard Center for Astrophysics told AFP.
“We’re looking at potentially the most distant starlight anyone has ever seen,” he said.
The farther objects are from us, the longer it takes for their light to reach us, and therefore to look into the distant universe is to see the deep past.
🚨 JWST potentially broke records by detecting a galaxy that existed when the universe was only 300 million years old! It took 13.4 billion years for the light from GLASS-z13 to hit us, but due to the expansion of the universe, the distance between us is now 33 billion light years! pic.twitter.com/5AcOBwHuO1
-Dr. James O’Donoghue (@physicJ) 20 July 2022
Although GLASS-z13 existed in the earliest period of the Universe, its exact age is unknown as it could have formed anytime within the first 300 million years.
GLASS-z13 was detected in what’s called an “early release” data from the orbiting observatory’s main infrared imager called NIRcam – but the discovery was not disclosed in the first set of images released by NASA last week.
When translated from the infrared to the visible spectrum, the galaxy appears as a red blob with white at its center as part of a wider view of the distant cosmos called the “deep field”.
Naidu and his colleagues – a team of 25 astronomers from around the world – presented their findings to a scientific journal.
Research for now published on a preprint serverso it comes with the caveat that it hasn’t yet undergone peer-reviewed – but it’s already got the global astronomy community on its feet.
“The astronomical record is already collapsing, and more is wobbly” tweeted out NASA chief scientist Thomas Zurbuchen.
“Yes, I tend to cheer only when scientific results become clear. peer review. But that looks very promising,” he added.
Another team of astronomers, led by Marco Castellano, working on the same data, came to similar conclusions, Naidu said, “so it gives us confidence.”
‘Work to be done’
One of Webb’s biggest promises is the ability to find the oldest galaxies that formed after the Big Bang 13.8 billion years ago.
Because they are so far from Earth, when their light reaches us, it has been stretched out by the expansion of the Universe and shifted to the infrared region of the light spectrum that Webb was equipped to detect with unprecedented clarity.
Naidu and his colleagues scanned this infrared data of the distant Universe, looking for an explanatory signature of extremely distant galaxies.
Below a certain infrared wavelength threshold, all photons – their energy packets – are absorbed by the neutral hydrogen of the Universe, located between the object and the observer.
Using data collected through different infrared filters pointing to the same region of space, they were able to detect where these drops in photons occurred, and from there infer the existence of these most distant galaxies.
“We searched all the early data for galaxies with this very striking signature, and these were by far the two systems with the most attractive signature,” Naidu said.
One of them is GLASS-z13, and the other is GLASS-z11, which is not as old as it used to be.
“There is strong evidence, but there is still work to be done,” said Naidu.
Specifically, the team would like to ask Webb’s executives to time the telescope to run spectroscopy—an analysis of light that reveals detailed features—to measure its precise distance.
“Currently our estimate of distance is based on what we can’t see – it would be great to have an answer to what we see,” said Naidu.
However, the team has already identified surprising features.
The galaxy, for example, is the mass of one billion Suns, which is “potentially very surprising, and that’s something we don’t really understand,” considering how soon after the Big Bang the galaxy formed.
Launched last December and fully operational since last week, Webb is the most powerful space telescope ever built, and astronomers are confident it will herald a new era of discovery.
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