An Australian-led team of astronomers has discovered a previously unknown galaxy just three billion years after the Big Bang. Described as a “cosmic” ring of fire” and “titanic donut,” the finding could change what we know about how the first galaxies formed.
Announced today in the journal The Nature Of Astronomythis “collision ring galaxy”—named R5519—is 10. thousands of millions of light-years away and is the first of its kind to be found in the early Universe.
“It is very curious object that we have never seen before,” said the principal investigator, Dr. Tiantian Yuan, Center for Astrophysics and Supercomputing at the Swinburne University of Technology, and the ARC Centre of Excellence for All-Sky Astrophysics 3-Dimensional (ASTRO 3D). “It seems strange and familiar at the same time.”
The publication of Yuan’s paper, “A giant galaxy in the young Universe with an enormous ring” it was accompanied by an incredible video produced by Swinburne University astro-animator James Josephides.
Where is R5519?
R5519 is 10.8 billion light-years away. She was photographed as it existed 11 billion years ago. What do you do as “looking back in time?” Yes—all of astronomy is looking back in time because the light that enters your eyes when the stars/or a telescope has travelled great distances through space at the speed of light to reach us. Even the light of the sun is 8 minutes of 20 seconds of age.
The Big Bang took place about 13.8 billion years; R5519 was photographed only three billion light years later.
How big is R5519?
Supermassive. The hole in R5519 of the “ring ” cosmic” has a diameter of two thousand millions of times greater than that of the Earth-Sun distance, astronomers call an astronomical unit (au), despite the fact that the galaxy itself has a similar mass to our own Milky way.
R5519 is also three million times larger than the diameter of the supermassive black hole in the galaxy M87, which was the first to be directly imaged in the last year.
Why is R5519 an incredible discovery?
This giant galaxy with a huge hole in the middle is a super-rare type of galaxy—a “collision ring galaxy”—that could shake-theories about how the first galaxies formed after the Big Bang, and how galaxies evolve. “It is making stars at a rate 50 times greater than the Milky way,” said Dr. Yuan. “Most of the activity that is taking place in your ring—so it truly is a ring of fire.”
How was R5519 discovered?
Working together with colleagues from Australia, USA, Canada, Belgium and Denmark, Dr Yuan used spectroscopic data collected by the W. M. Keck Observatory in Hawaii and the images recorded by the NASA, the Hubble Space Telescope to identify R5519 the unusual structure.
Why is R5519 an important discovery?
R5519 is the first known “collisional ring galaxy” that has been found in the early Universe, and it is likely that the outcome of a violent encounter with other galaxies. Their discovery has implications for the understanding of how spiral galaxies like our own Milky way was formed.
That is because the ring galaxies as the R5519 are very rare in the local Universe. In fact, they represent just the 0,01% of the galaxies, and are formed by head-on collisions. This paper suggests that the tremendous collision rings are so rare to 11.8 billion years ago as they are today.
“The collision of galaxy formation of the ring requires a thin disk to be present in the “victim” of the galaxy before the collision occurs,” said co-author Professor Kenneth Freeman of Australian National University. “The thin disk is the definition of the components of spiral galaxies: before they are assembled, the galaxies were in a disorderly state, is not yet recognizable as spiral galaxies.”
“In the case of this ring galaxy, we are looking back at the early Universe 11 billion years ago, in a time when thin disks were only mounting,” said Freeman. “This discovery is an indication that the disc assembly in the spiral galaxies occurred during a more extended period of time than I thought.”
For comparison, the thin disk of our galaxy, the Milky way began to come together only around nine thousand million years ago.
Wishing you clear skies and great eyes.