The James Webb Space Telescope is helping us understand galaxies extremely different from our own and how galaxies similar to the Milky Way were first formed as it looks back at some of the first galaxies. Recently, astronomers reported using Webb to find some of the earliest galaxies with stellar bars, a characteristic that makes them comparable to our barred spiral galaxy today.
The term “galaxy bar” refers to a structure made of dust and gas that spans a galaxy’s centre and may often be seen in photographs as a brilliant stripe. These formations are hypothesized to form as the galaxy ages, drawing dust and gas toward the galactic centre. Therefore, it was amazing to spot a bar in a galaxy that dates back to when the universe was just 25% as old as it is today.
The new Webb view of galaxy EGS23205 displays a bright bar structure far more clearly than the Hubble image, which was previously smudged and difficult to see any structure in. We are dumping everything else, said Shardha Jogee of the University of Texas at Austin, one of the researchers. We are dropping everything else, I screamed after taking a quick look at this data. The amazing ability of JWST to see the underlying structure of galaxies is demonstrated by how the bars in the JWST image “just leapt out” of the Hubble data.
Webb also captured an image of EGS-24268, a galaxy estimated to be 11 billion years old. It’s exciting to discover these features in extremely young galaxies since it implies that scientists need to modify their theories about how they develop. As they move gas and provide the raw materials for the formation of new stars, bars are thought to be crucial for the growth of galaxies.