The James Webb Space Telescope has already stunned the world with the deepest image of space ever taken in the infrared, and now it has another feather in its cap — the potential discovery of the most distant galaxy ever observed.
Early data is coming in from a survey called the Grism Lens-Amplified Survey from Space, or GLASS, which uses both Webb’s NIRCam camera and its NIRISS and NIRSpec spectrographs to observe a galaxy cluster called Abell 2744. The aim of the survey is to look back at a very early period after the Big Bang called the Epoch of Reionization, when the first starlight shone through the universe. It’s possible to see very distant galaxies because the mass of Abell 2744 is so great that it warps spacetime, acting as a magnifying glass for the faint galaxies behind it.
In the first batch of data from GLASS, researchers have identified two galaxies that have very high redshifts, meaning that their light is shifted far into the infrared range which indicates they are exceedingly far away. The results indicate that we could be seeing the two galaxies as they were 13.4 billion years ago. “We’re potentially looking at the most distant starlight that anyone has ever seen,” lead author Rohan Naidu said to AFP.
These results were collected with the NIRCam instrument, so they still need to be confirmed with further readings such as spectroscopy results from NIRSpec. The paper has also not yet been peer-reviewed, so the results should be considered speculative at this point until further confirmation is released. But the work gives an exciting preview of the kind of results that will be possible with James Webb.
The older of the two galaxies, called GLASS-z13, could be from one of the earliest stages of the universe, within 300 million years after the Big Bang. If the results are confirmed, that would make it the most distant galaxy ever observed. “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!” physicist James O’Donoghue explained on Twitter.
The research is available to view on pre-print archive arXiv.
