A study of an ancient spiral galaxy reveals important information about early galaxy formation, highlighting rapid star formation and unique structural features compared to modern galaxies.

A new image of an ancient, distant galaxy could help scientists understand how it formed and the origin of the Milky Way. More than 12 billion years old, BRI 1335-0417 is the oldest and most distant known spiral galaxy in the Universe. The lead author of the study, Dr. Takafumi Tsukui said that a state-of-the-art telescope called ALMA allowed them to look at this ancient galaxy in much more detail.

Dr. “We were particularly interested in how gas moves within and across the galaxy,” Tsukui said. “Gas is an important component in star formation and can give us important clues about how the galaxy actually contributes to star formation.”

Revealing galactic motion and structure

In this case, researchers were not only able to record the movement of gas around BRI 1335-0417, but also detect seismic wave formation in such early galaxies for the first time. The galaxy’s disk, a flattened mass of spinning stars, gas, and dust, moves in a way not unlike the waves emitted after a stone is thrown into a pond. This new data means we now know more about how the galaxy formed.

“The vertical oscillatory motion of the disk is caused by either new gas entering the galaxy or an external source from contact with other smaller galaxies,” Dr Tsukui said. said.

“Both possibilities would bombard the galaxy with new fuel for star formation.

“Our study also revealed a rod-like structure in the disk. Galactic rods can distort gas and transport it to the center of the galaxy. The nucleus found in BRI 1335-0417 is the most distant known structure of its kind.”

“Together these results demonstrate the dynamic growth of a young galaxy.”

A simulation showing the formation of a spiral galaxy

A look into the past

Because BRI 1335-0417 is so far away, its light takes longer to reach Earth. The images we see through the telescope today are from the galaxy’s early days, when the universe was only 10 percent of its current age.

“Early galaxies have been found to form stars much faster than modern galaxies. This is the case for BRI 1335-0417, which, despite having a similar mass as our own Milky Way, forms stars hundreds of times faster,” said co-author Associate Professor Emily Wisnioski. “We wanted to understand how the gas was provided to keep up with such rapid star formation.

The role of spiral structures

“Spiral structures are rare in the early universe, and exactly how they formed is unknown. This research also gives us important information about the most likely scenarios. “Although it is impossible to directly observe the evolution of a galaxy, since our observations only give us a snapshot, computer simulations tell the story. It can help put the pieces together.”