Most Ancient Spiral Galaxy May Shed Light On Evolution Of Milky Way
Astronomers have found and studied the most ancient spiral galaxy in the universe, which existed just 2.6 billion years after the Big Bang, at the time when the universe is still at its infancy.
Most Ancient Spiral Galaxy
Scientists confirmed the vintage and spiral nature of the galaxy using gravitational lensing and the instruments at the Near-infrared Integral Field Spectrograph of the Gemini North telescope in Hawaii.
The galaxy called A1689B11 has been around for almost 11 billion years and is thus considered the most ancient spiral galaxy that scientists have so far discovered.
"We report an integral-field spectroscopic (IFS) observation of a gravitationally lensed spiral galaxy A1689B11 at redshift z=2.54. It is the most ancient spiral galaxy discovered to date and the second kinematically confirmed," researchers reported.
Gravitational lenses are produced by massive clusters of dark matter and galaxies. They serve as cosmic telescopes. The phenomenon, which was first predicted by physicist Albert Einstein, occurs when the cluster bends the light from galaxies behind it, similar to what happens in an ordinary lens.
The effect is used to examine distant galaxies that are normally too far from Earth for scientists to study. Study researcher Tiantian Yuan, from the Swinburne University of Technology, said that the technique also allows them to more thoroughly study ancient galaxies and in unprecedented detail.
Spiral Galaxies Exceptionally Rare In The Early Universe
The study revealed surprising features of A1689B11. Researchers said that like other young galaxies of similar masses, the galaxy forms stars 20 times faster than the galaxies today.
Odd Characteristics Not Found In Other Ancient Spiral Galaxies
When scientists examine galaxies in early era, they usually find that turbulence has a much greater role than it does in younger galaxies. Unlike other galaxies that hail from the same epoch, A1689B11 is characterized by a very cool and thin disc. It also rotates calmly with little turbulence.
Scientists have never before seen spiral galaxies from this early period of the universe with these characteristics.
Study researcher Renyue Cen, from Princeton University, said that spiral galaxies occur rarely in the early universe. The discovery of A1689B11 may shed more light on how galaxies, including our very own Milky Way, have evolved.
"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," Cen said.