MELBOURNE: Scientists have discovered the most ancient spiral galaxy in the universe that existed 11 billion years ago and could provide insights into the early cosmos.
The galaxy, known as A1689B11, existed just 2.6 billion years after the Big Bang, when the universe was only one fifth of its present age.
Researchers including those from Australian National University (ANU) and Swinburne University of Technology used a powerful technique that combines gravitational lensing with the Near-infrared Integral Field Spectrograph (NIFS) on the Gemini North telescope in Hawai'i to verify the vintage and spiral nature of the galaxy.
Gravitational lenses are nature's largest telescopes, created by massive clusters composed of thousands of galaxies and dark matter.
The cluster bends and magnifies the light of galaxies behind it in a manner similar to an ordinary lens, but on a much larger scale.
"This technique allows us to study ancient galaxies in high resolution with unprecedented detail," said Tiantian Yuan from ANU.
"We are able to look 11 billion years back in time and directly witness the formation of the first, primitive spiral arms of a galaxy," said Yuan, who led the research team.
"Studying ancient spirals like A1689B11 is a key to unlocking the mystery of how and when the Hubble sequence emerges," said Renyue Cen from Princeton University in the US.
"Spiral galaxies are exceptionally rare in the early universe, and this discovery opens the door to investigating how galaxies transition from highly chaotic, turbulent discs to tranquil, thin discs like those of our own Milky Way galaxy," said Cen.
"This galaxy is forming stars 20 times faster than galaxies today – as fast as other young galaxies of similar masses in the early universe," he said.
"However, unlike other galaxies of the same epoch, A1689B11 has a very cool and thin disc, rotating calmly with surprisingly little turbulence. This type of spiral galaxy has never been seen before at this early epoch of the universe," said Cen.