Since the launch of the Hubble Space Telescope, astronomers have been able to look a little further into the cosmic web. The deeper we have looked, the more we have traveled in time, contemplating and learning what the universe was like billions of years ago.
Now an international team of astronomers has used the LMT telescope to detect a galaxy 12.8 billion light-years away. Thanks to a new technique that combines gravitational lensing and spectrography, astronomers were able to see an object that was born shortly after the Big Bang, making this galaxy called G09 83808 , the oldest object ever detected by the LMT (Large Millimeter Telescope ).
The study, published in Nature Astronomy, details that the team relied on gravitational lensing to detect it. This technique, which involves using a large object – such as a galactic cluster – to bend and magnify the light of a galaxy behind it, has become a mainstay for the world of astronomy.
“The Big Bang occurred 13.7 billion years ago, so (the observed galaxy) was forming within the first billion years after the Big Bang. Seeing an object within the first billion years is remarkable because the The universe was completely ionized, meaning it was too hot and uniform to form anything, for the first 400 million years. For this reason, astronomers believe that the first stars and galaxies and all black holes formed inside first 500 million to one billion years. This new object is very close to being one of the first galaxies to form, “explains Min Yun, leader of the work.
The most distant spiral galaxy
Astronomers have also discovered what is the most distant spiral galaxy in the known universe, named A1689B11. The discovery of such an ancient spiral galaxy is crucial in determining when and how the first galaxies began to change from elliptical to modern shapes.
“This technique allows us to study ancient galaxies in high resolution with unprecedented detail. We can look back 11 billion years in time and be direct witnesses to the formation of the first and primitive spiral arms of a galaxy,” explains Tiantian Yuan, leader of the work published in Astrophysical Journal.
They then used the Near Infrared Integral Field Spectrograph (NIFS) at the Gemini Observatory to verify the structure and nature of this spiral galaxy. Thanks to this latest discovery, astronomers now have some additional clues about how galaxies ended up taking the shapes with which we are familiar today.
Recall that based on the traditional classification scheme developed by the astronomer Edwin Hubble, galaxies are divided into 3 groups according to their shape or visual morphology: elliptical, spiral and irregular.
“Studying ancient spirals like A1689B11 is the key to uncovering the mystery of how and when the Hubble sequence emerges. Spiral galaxies are exceptionally rare in the early universe , and this discovery opens the door to investigate how galaxies move from turbulent disks and highly chaotic to calm and thin discs like those of our Milky Way galaxy “, comments Renyue Cen, co-author of the work.
This spiral galaxy is creating stars 20 times faster than today’s galaxies , “as fast as other young galaxies of similar masses in the early universe,” the scientists warned. However, it has a very thin disc that rotates slowly. “This type of spiral galaxy has never been seen before at this time in the Universe!” Declares Cen.
These surprising features could challenge our understanding of this period in cosmic history, as such qualities contrast with today’s galaxies.
In the future, the team hopes to conduct further studies of this galaxy to further unravel its structure and nature, and compare it with other spiral galaxies from this time in the universe.
Referencia: “The most ancient spiral galaxy: a 2.6-Gyr-old disk with a tranquil velocity field” Tiantian Yuan et al. The Astrophysical Journal 2017 DOI: arxiv.org/pdf/1710.11130.pdf
A dusty star-forming galaxy at z = 6 revealed by strong gravitational lensing. Nature Astronomy, 2017; DOI: 10.1038/s41550-017-0297-8
