Key Takeaways:
- Astronomers have discovered a galaxy, ID2299, that is slowly dying because it is losing cold gas, the fuel it needs to form new stars.
- The galaxy is losing cold gas at an alarming rate, enough to make 10,000 suns every year.
- It is believed that the galaxy’s demise is due to a massive collision with another galaxy in the past.
- This discovery suggests that galactic mergers may be a more common cause of galaxy death than previously thought.
- The finding could also provide clues about the future of our own Milky Way galaxy, which is also on track to collide with another galaxy in a few billion years.
For the first time, astronomers can clearly see a galaxy beginning to die.
Galaxy ID2299, located nine billion light-years away, is losing vital cold gas that is needed to form new stars. It leaks out enough gas annually to make 10,000 suns. Almost half of its cold gas has already been lost. The remaining material is being consumed hundreds of times more quickly than in the Milky Way to form new stars.
The galaxy will soon run out of extra gas and be unable to produce new stars at this rate. A galaxy would die for that.
The research team that found ID2299 and its coming demise released their findings in the journal Nature Astronomy.
It is believed that ID2299 originated from the merger of two galaxies that collided and formed a new galaxy. The resulting galaxy is recognizable by its prominent “tidal tail,” which is made up of interstellar material and star streams that extend into space.
Tidal tails often form when galaxies’ outer layers get stripped away as they merge. Such tails in distant galaxies are usually too dim for astronomers on Earth to see, though they have been detected on hundreds of galaxies. The researchers spotted this one just as it started to extend into space. That’s where all the gas is escaping.
According to the research, massive collisions may cause galaxies to leak essential gases into space, which will eventually cause them to starve and stop star formation, ultimately leading to their demise.
Lead author Annagrazia Puglisi of Durham University in England said in a press release that “this is the first time we have observed a typical massive star-forming galaxy in the distant universe about to ‘die’ because of a massive cold-gas ejection.”
More than one way to ‘die’
Star formation results in winds. Every massive galaxy, according to scientific theory, has a black hole at its center that produces wind from the material it consumes when it comes into contact with it. According to astronomers, star-forming material is eventually carried into far-off space by the winds from stars and black holes, which leads to the eventual death of galaxies.
However, the finding of the gas-leaking tail of ID2299 indicates a different route to galactic death.
According to the press release, co-author of the study and astrophysicist at the Saclay Nuclear Research Center in France Emanuele Daddi said, “Our study suggests that gas ejections can be produced by mergers, and that winds and tidal tails can appear very similar.” “This might lead us to revise our understanding of how galaxies ‘die.'”
The discovery might also provide indications about the future of our own galaxy. The Milky Way is shooting puffs of its own cold gas into the void, and it’s also on track to collide with the Andromeda Galaxy in about 4 billion years.
“Witnessing such a massive disruption event adds an important piece to the complex puzzle of galaxy evolution,” Chiara Circosta, a co-author of the study and researcher at the University College London, said in the release.
Using the Chilean desert’s Atacama Large Millimeter/submillimeter Array (ALMA) to study cold gas in 100 distant galaxies, the researchers stumbled upon this doomed galaxy.
“I was eager to learn more about this weird object because I was convinced that there was some important lesson to be learned about how distant galaxies evolve,” said Puglisi.
