UT research team discovers barred galaxy in young universe

Sophia Kurz, General News Reporter

Researchers at UT have discovered barred galaxies similar to the Milky Way for the first time at earlier epochs of the universe at only a quarter of its current age. 

A bar is an elongated structure of stars that starts in the center of a galaxy and extends out into the outer disk of the galaxy, astronomy professor Shardha Jogee said.

Jogee said the bars take the gas from the outer part of the galaxy and channel it into the center, just like raw materials go from a harbor to a factory in the city.

“(The bar is) solving the supply chain problem by taking the gas from the outer disk of the galaxy, bringing it to the center of the galaxy, and then the center of the galaxy is where the gas gets converted into stars at a very, very fast rate,” Jogee said.

The discovery of barred galaxies can be attributed to the James Webb Space Telescope, which produces more powerful and higher resolution images of space than its predecessor, the Hubble Space Telescope, Jogee said.

“The Webb works at long infrared wavelengths, where it can look through the dust in the galaxy and see the underlying distribution of stars and see the bars,” Jogee said.

The reason this discovery of barred galaxies at such an early stage in the universe matters is that, up until now, scientists could trace their existence up to 10 billion years ago. The discovery will now provide a better insight into how the universe has evolved over time, said astronomy senior Eden Wise, who assisted with the discovery.

Micaela Bagley, a postdoctoral fellow in astronomy and collaborator on the Cosmic Evolution Early Release Science Survey, supported the research efforts by reducing the images provided by the Webb telescope to the whole survey team. Jogee and astronomy graduate student Kay Guo visually identified the barred galaxies in the images and conducted various analyses.

“What I did is a well-known technique called ellipse fitting,” Guo said. “We’re very excited that we actually found some (bars) because there are multiple simulations and multiple theories that actually produce different results (about barred galaxies).”

Stars like the sun are important to human life, said Eva Chen, a physics, math and astronomy senior who also assisted with the discovery. Since barred galaxies are important for the rapid formation of new stars, understanding barred galaxies better will help us understand new ways to form stars.

The next step from this discovery is studying bar fractions, which will help with understanding what fraction of galaxies at different stages of the universe are barred. This will give scientists a better understanding of how the universe has evolved, Guo said.