Death of a distant galaxy: Astronomers capture dying galaxy for the first time

Astronomers have recently observed a rare phenomenon in space: the death of a distant galaxy. The study of this phenomenon has been published in Nature Astronomy, where the research is being carried out by an international team of astronomers from the University of Durham.

ESO (European Southern Observatory) has published a release which reveals details about this rare phenomenon.

“Using the Atacama Large Millimeter/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, astronomers have seen a galaxy ejecting nearly half of its star-forming gas. This ejection is happening at a startling rate, equivalent to 10 000 Suns-worth of gas a year — the galaxy is rapidly losing its fuel to make new stars,” states the press release.

A collision with another galaxy triggered this space event, according to the team. This has helped  astronomers analyze how galaxies stop bringing new stars to life.

“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,” says Annagrazia Puglisi, lead researcher on the new study, from the Durham University, UK, and the Saclay Nuclear Research Centre (CEA-Saclay), France.

The press release goes on to say that the event behind the dramatic gas loss is a collision between two galaxies that eventually merged to create “ID2299”.

The clue that led the scientists to this scenario was also the association of the expelled gas with a “tidal tail” described as elongated streams of stars and gas that extend into interstellar space and result from the merger of two galaxies. This “tidal tail” is generally too faint to be seen in distant galaxies.

“Our study suggests that gas ejections can be produced by mergers and that winds and tidal tails can appear very similar,” says study co-author Emanuele Daddi of CEA-Saclay. “This might lead us to revise our understanding of how galaxies ‘die’,” added Daddi.