Giant galaxies die from within when they stop forming stars. For the first time, astronomers have detected this phenomenon in a distant galaxy.
Scientists spotted the phenomenon in the galaxy after it had ejected almost half of the gas it uses to form stars. They captured the rare phenomenon using the Atacama Large Millimeter/submillimeter Array in Chile.
The light from this galaxy, known as ID2299, took about nine billion years to reach Earth. This means astronomers are essentially observing how it appeared when the universe was just 4.5 billion years old (now estimated to be 14 billion years old).
Galaxy ID2299 is losing gas every year, which reduces the fuel it needs to form stars. But the galaxy is still forming stars at a rate hundreds of times faster than our own Milky Way. This will essentially cause ID2299 to die in a few tens of millions of years.
The study was published Monday in the journal Nature Astronomy.
"This is the first time we have detected that a typical star-forming galaxy in the distant Universe 'dies' due to a massive ejection of cold gas," said Annagrazia Puglisi, lead study researcher and postdoctoral researcher from Durham University in the United Kingdom and the Saclay Nuclear Research Center in France.
It is possible that the death of this galaxy was caused by a collision with another galaxy, which eventually merged to create ID2299.
If a merger has led to the loss of gas from this galaxy, astronomers may need to reconsider theories about the end of star formation in galaxies. Astronomers using ESA's Herschel space observatory have found that winds blowing from a supermassive black hole are sweeping away the host galaxy's supply of star-forming material.
Perhaps the best part of this discovery is that it was made while the astronomers were working on a separate study of cold gas in distant galaxies. They observed the phenomenon in ID2299 for just a few minutes, but it was enough to gather some initial information and even take a picture of the galaxy.
Astronomers' future observations of the galaxy could reveal more about the gas being ejected from the galaxy.
Information source: ctvnews.ca
