Evrim Yazgin
Cosmos science journalist
The James Webb Space Telescope (JWST) has provided the first glimpse of very compact structures of star clusters in distant galaxies. The so-called clumps were studied in JWST’s first images of galaxy clusters.
These images have allowed researchers to study the first phase of star formation in the galaxies.
They were aided in their analysis by gravitational lensing – an effect whereby massive objects like galaxies, bend light coming from behind them, causing a zoom-in effect which helps astronomers see distant objects more clearly.
“The galaxy clusters we examined are so massive that they bend light rays passing through their centre, as predicted by Einstein in 1915. And this in turn produces a kind of magnifying glass effect: the images of background galaxies are magnified,” explains Adélaïde Claeyssens, a postdoc at Stockholm University.
Add to the gravitational lensing JWST’s superior resolution and the astronomers were able to detect very compact galaxy structures. The team was able to glean new insights into the links between clump formation and the evolution and growth of galaxies in a way that was not possible before.
The light from the furthest of the galaxies studied has taken 13 billion years to reach Earth, so we are seeing the galaxy as it was when the Universe itself was only 680 million years old.
Read more: New map of all the matter in the universe reveals the cosmos is less “clumpy” than we thought
But Webb has allowed astronomers to see even further into the past.
Late last year, it broke its own record, finding the oldest confirmed galaxy. It existed only 325 million years after the Big Bang.
“The images from the James Webb Space Telescope show that we can now detect very small structures inside very distant galaxies and that we can see these clumps in many of these galaxies. The telescope is a game-changer for the entire field of research and helps us understand how galaxies form and evolve,” says Assistant Professor Angela Adamo, also from Stockholm University.
The research is published in Monthly Notices of the Royal Astronomical Society.