Everything has an expiration date, from the milk in your fridge to the Milky Way Galaxy.
According to CBS News, galaxies begin to die when all of the stars within them die and no new replacements are generated. In these instances, all of a galaxy’s gas is ejected, making it impossible for new stars to form. Once that happens, the galaxy itself “ceases to exist.”
CNN reports that, with the help of the Atacama Large Millimeter/submillimeter Array of telescopes in Chile, scientists managed to catch a glimpse of a distant galaxy entering its final stages of life as it ejected nearly half of the gas it uses to form stars. Researchers from Durham University published their findings in an article featured to Phys.org.
New research led by Durham University in the United Kingdom, the French Alternative Energies and Atomic Energy Commission (CEA)-Saclay and the University of Paris-Saclay, shows that a huge amount of star-forming gas was ejected into the intergalactic medium by the coming together of two galaxies.
The galaxy in question is known by astronomers as ID2299, a galaxy that’s positioned so far away from Earth that its light takes about 9 billion years of travel to get here.
This means that when astronomers gaze upon ID2299 through their fancy telescopes, they’re essentially looking into the galaxy’s past and studying how it was behaving when the universe was just 4.5 billion years old. (According to CNN, the universe is approximately 14 billion years old.)
An artist's impression of #galaxy ID2299 as it ejects star-forming gas into the #universe. Our astronomers looked back 9 billion years to see how mergers like that which formed ID2299 could shut down #starformation & affect galaxy growth: https://t.co/5gZ8P2MV6b#DUResearch pic.twitter.com/D3Oum5smn4— Durham University (@durham_uni) January 11, 2021
Annagrazia Puglisi, a postdoctoral research associate from Durham University in the U.K. recently commented on the observations in a statement, via CNN. She said:
“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.”
CBS News reports that ID2299 is losing 10,000 suns per year and it is rapidly exhausting the fuel it needs to generate new ones in the process. According to CNN, ID2299 is simultaneously forming stars at a rate that’s several hundred times faster than that of our Milky Way galaxy, effectively draining the remainder of its precious gas supply. This specific behavior is what’s leading astronomers to believe that, in a few tens of thousands of years, the galaxy will be no more.
The current theory is that ID2299 began exhibiting this behavior after it collided with another galaxy, CNN reports. According to one of the study’s co-authors, Dr. Jeremy Fensch, the confirmation of their theory could force astronomers to reconsider previous theories about galactic life cycles. He said (via CBS News):
“Studying this single case unveiled the possibility that this type of event might not be unusual at all and that many galaxies suffered from this ‘gravitational gas removal’, including misinterpreted past observations. ... This might have huge consequences on our understanding of what actually shapes the evolution of galaxies.”