Astronomers have, for the first time, witnessed the death of a distant galaxy, which they describe as a “truly extreme event.”
When all of the stars in a galaxy die, and new ones are no longer forming, the galaxy itself ceases to exist. This occurs when all of the galaxy’s gas is ejected, making it impossible for new stars to form.
According to a study published Monday in the journal Nature Astronomy, scientists were “thrilled” 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 starburst galaxy ID2299 to reach Earth. So, when astronomers happened to observe it by chance, they witnessed the universe as it appeared at just 4.5 billion years old.
Astronomers say that ID2299 is losing 10,000 suns worth of gas each year — rapidly depleting fuel needed to form new stars. This startling release of gas appears to be the result of two galaxies violently colliding and merging together to create ID2299.
The galaxy is also currently forming stars at a rate hundreds of times faster than the Milky Way — using up the rest of its precious gas supply. Because of this, ID2299 is expected to die relatively soon, in just 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 about to ‘die’ because of a massive cold gas ejection,” lead author Annagrazia Puglisi said in a statement.