JWST has broken the record for the most distant galaxy ever confirmed

The James Webb Space Telescope has spotted the most distant galaxy ever definitively confirmed, which formed about 325 million years after the big bang

By Lea Crane

The James Webb Space Telescope (JWST) spotted the most distant galaxies never confirmed. Although he has seen many galaxies that seem extraordinarily distant, these are the first with evidence proving that they are as distant as they appear.

Astronomers measure distances to cosmic objects using a metric called red shift. Because of the expansion of the universe, the farther an object is from Earth, the faster it is moving away from us. Similar to the Doppler effect, in which a sound appears to rise or fall in pitch as it gets closer to or further from the listener, the color of light from a galaxy becomes redder as it travels. goes away quickly. By comparing a galaxy’s red color to calculations of its actual color, astronomers can determine how far away a galaxy really is.

In first observations of galaxies by JWST, astronomers could only make an approximation of each galaxy’s redshift because they did not have detailed data on the spectra of the light coming from these galaxies. These observations provided clues to galaxies with redshifts of 12 and greater, meaning they appear to be over 30 million light-years away and would have formed within 400 million years of the big bang – but many scientists viewed these findings with skepticism due to the lack of precise confirmation.

“It was crucial to prove that these galaxies indeed inhabited the early universe,” said Emma Curtis Lake at the University of Hertfordshire in the UK a NASA blog post. “It is very possible that closer galaxies will pass themselves off as very distant galaxies.”

Now, as part of the JWST Advanced Deep Extragalactic Survey (JADES), researchers have confirmed the redshifts of four extremely distant galaxies, ranging from about 10.4 to 13.2. This means that they were formed between 325 million and 450 million years from the big bang. The previous record for the highest confirmed redshift was around 11.

“These are by far the faintest infrared spectra ever taken,” said Stefano Carniani at the Scuola Normale Superiore in Italy. The observations lasted 28 hours over three days and covered a total of 250 faint galaxies, with another round of observations scheduled for 2023. It should confirm even more of these distant galaxies, which will tell us about the early days of the formation of galaxies and how the most distant galaxies differ of those in our cosmic neighborhood.

Reference: arxiv.org/abs/2212.04480

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