Atacama Large Millimeter Array Captured Spiral Galaxy

Astronomers have identified the oldest known Spiral Galaxy in the universe, which was formed around 12.4 billion years ago, after rediscovering a fuzzy, forgotten photo taken by the Atacama Large Millimeter Array. The new galaxy, which is called BRI 1335-0417, measures 15,000 light-years across, making it a third as big as our spiral-shaped home galaxy, the Milky Way.

The galaxy formed around 1.4 billion years after the Big Bang which makes it the earliest example of a Spiral Galaxy. It beats the previous oldest spiral, detected in 2019, by around 1.1 billion years. The oldest known galaxy in existence remains GN-z11, which formed around 400 million years after the Big Bang.Researchers discovered the ancient galaxy after finding a photo of it in the Atacama Large Millimeter Array archive. To the untrained eye, the image may look blurry, but it contains a surprising amount of detail for such a distant galaxy.

Takafumi Tsukui, lead author a graduate student at The Graduate University for Advanced Studies, SOKENDAI in Japan shared his excitement that he had never seen such clear evidence of a rotating disk, spiral structure and centralized mass structure in a distant galaxy in any previous literature. The quality of the Atacama Large Millimeter Array data was so good that researchers saw so much detail that they thought it was a nearby galaxy.

The researchers believe that it holds the same amount of mass as the Milky Way, despite being much smaller, and that its spiral arms were likely hotspots for star formation. The galaxy could be so dense because it formed from a violent collision between two smaller galaxies.BRI 1335-0417 could also provide some clues to what eventually happens to the Spiral Galaxy.  Astronomers believed that spirals are precursors to elliptical galaxies, but exactly how this transformation occurs is still a mystery.