Astronomers have for the first time witnessed the death of a distant galaxy, which they describe as a “truly extreme event.”
When all the stars in a galaxy die and new ones no longer form, the galaxy itself ceases to exist. This happens when all the galaxy’s gas is pushed out, making it impossible for new stars to form.
According to a study published Monday in the journal Nature Astronomy, scientists were “excited” to be able to capture this rare phenomenon recently using the Atacama Large Millimeter / submilimeter Array of Telescopes in Chile.
It has taken about nine billion years for the light from the constellation galaxy ID2299 to reach Earth. So when astronomers happened to observe it by chance, they witnessed the universe when it appeared just 4.5 billion years old.
Astronomers say that ID2299 loses 1
The galaxy is also currently forming stars at a speed hundreds of times faster than the Milky Way – by using up the rest of its precious gas supply. Because of this, ID2299 is expected to die relatively soon in a few tens of thousands of years.
“This is the first time we have observed a typical massive star-forming galaxy in the distant universe by ‘dying’ due to a massive cold gas exhaust,” lead author Annagrazia Puglisi said in a statement.
Astronomers believe that the phenomenon is the result of galaxies melting together because they were able to witness a rare “tidal tail”, usually too faint to see in distant galaxies. Astronomers suggest that this elongated stream of stars and gas is the direct result of the galactic fusion.
They only observed the galaxy for a few minutes, but that was enough to spot the elusive tide.
“Our study suggests that gas emissions can be produced by mergers, and that wind and tidal halls may seem very similar,” says study co-author Emanuele Daddi. “This may lead us to revise our understanding of how galaxies ‘die’.”
If astronomers are right that the fusion led to the massive loss of gas, they will have to reconsider previous theories about how galaxies form and evolve – and how they die. Other theories have suggested that winds from active black holes or intense star formations are responsible for such deaths.
“Studying this single case revealed the possibility that this type of event was not unusual at all, and that many galaxies suffered from this ‘gravitational pull’, including interpreting past observations,” said co-author Dr. Jeremy Fensch.
“This could have huge implications for our understanding of what actually shapes galaxy evolution.”