The stunning image shows a dying galaxy emitting 10,000 gas suns a year after a huge collision – weakening its ability to form stars
- Researchers observed the galaxy when the universe was 4.5 billion years old
- The expelled gas was probably the result of a previous fusion with another galaxy
- This gas leak actually made the galaxy no longer produce new stars
A sensational image of a dying galaxy – emitting 10,000 suns each year due to a large collision – was captured by an international team of astronomers.
New research led by Durham University has looked back nine billion years for evidence that galaxy mergers in the early universe could stop star formation.
These fusions force the gas to drain from the galaxy and weaken its ability to form new stars, effectively marking the end of its life as an active body.
The team found that a huge amount of star-forming gas was released into the intergalactic environment by reuniting two galaxies.
The researchers say that this event, along with a large amount of star formation in the nuclear regions of the newly merged galaxy – dubbed ID2299 – will eventually deprive the single fused body of the fuel needed to form new stars.
This would stop the formation of stars for several hundred million years, effectively stopping the development of the galaxy.
This artist’s impression of ID2299 shows the galaxy, the product of a galactic collision and part of its gas being evacuated by a “tidal tail” as a result of the fusion
Thanks to the time it took for the light from ID2299 to reach Earth, researchers were able to see the galaxy as it appeared nine billion years ago when it was in the late stages of its fusion.
This is a time when the universe was only 4.5 billion years old and in the most active phase of the “young adult” – compared to a human life.
Using the Atacama Large Millimeter Array (ALMA) telescope at the European Southern Observatory in northern Chile, the researchers saw that it removes about half of its total gas tank around the galaxy, at a rate equivalent to 10,000 suns worth of gas each year.
The lead author, Dr Annagrazia Puglisi of the Durag University Center for Extragalactic Astronomy, said: “We do not yet know the exact processes behind stopping star formation in massive galaxies.
“It is considered that the winds caused by feedback from star formation or active black holes are mainly responsible for expelling gas and extinguishing growth.
“Our research provides evidence that the gas discharged from ID2299 is likely to have been ejected due to the fusion of two gas-rich galaxies.
“The gravitational interaction between two galaxies can thus provide a sufficient angular momentum to release some of the gas around the galaxy.
“This suggests that mergers are also able to alter the future evolution of a galaxy by limiting its ability to form stars over millions of years and are worth further investigation when we consider the factors that limit the growth of the galaxy.” .
The researchers were able to exclude the formation of stars and the active black hole of the galaxy as a reason for this ejection by comparing their measurements with previous studies and simulations and by measuring the physical properties of the escaped gas.
The rate at which gas is expelled from ID2299 is too high to be caused by energy from a black hole or starburst, as seen in previous studies.
The researchers say the simulations suggest that no black hole can emit as much cold gas from a galaxy as it was expelled from ID2299.
The excitation of the exhaust gas is also not compatible with the wind generated by a black hole or the birth of new stars.
Using the Atacama Large Millimeter Array (ALMA) telescope at the Southern European Observatory in northern Chile, researchers saw that it was removing about half of its total gas tank in the vicinity of the galaxy.
Co-author Dr. Emanuele Daddi, from CEA-Saclay, said: “This galaxy is witnessing a truly extreme event.
“He is probably caught during an important physical phase for the evolution of the galaxy that takes place in a relatively short time. We had to look at over 100 galaxies with ALMA to find it. “
Co-author Dr. Jeremy Fensch of the Center de Recherche Astrophysique in Lyon added: “The study of this unique case revealed the possibility that this type of event is not at all unusual and that many galaxies have suffered this” gravitational gas elimination. ”. , including misinterpreted past remarks.
“This could have huge consequences for our understanding of what actually shapes galaxy evolution.”
Researchers now hope to obtain higher-resolution images of ID2299 and other distant galaxy mergers and perform computer simulations to further understand the effect of galaxy mergers on the life cycle of galaxies.
The findings are published in the journal Nature Astronomy.
WHAT IS THE SOUL?
Deep in the Chilean desert, the Atacama Large Millimeter Array or ALMA is located in one of the driest places on Earth.
At an altitude of 16,400 ft, about half the cruising height of a jumbo jet and almost four times that of Ben Nevis, workers had to carry oxygen tanks to complete their construction.
Launched in March 2013, it is the most powerful telescope in the world.
It is also the largest on the planet and, with almost 1 billion pounds ($ 1.2 billion), one of the most expensive of its kind.
Deep in the Chilean desert, the Atacama Large Millimeter Array or ALMA is located in one of the driest places on Earth. Launched in March 2013, it is the most powerful telescope in the world