First-Ever Galaxy’s Death Caught on Human Eyes & What Does It Mean?

Supernovas or dying stars are rare. Once in a few decades can someone witness a cosmic phenomenon like this with their own eyes. But you know what’s even rarer? A galaxy’s death. In fact, it is so rare that this is the very first time we, humans were able to observe this astronomical event, thanks to the Atacama Large Millimeter/sub-millimeter Array of telescopes placed in Chile and a team of keen-eyed observers.

The witnessing team of astronomers is calling it a “truly extreme event” due to the scarcity of this event.

Witnessing such an event is very scarce, mainly because the galaxies are so far from us that it literally takes billions of years for light to reach such a galactic demise. So, when the astronomers observed it, they were witnessing the universe, more specifically the galaxy, as it appeared around 9 billion years ago.

According to the study published by Nature Astronomy Journal, the observed dying Galaxy, was only 4.5 billion years old when the researchers observed the tidal tail of what can only be described as the last stages of that galaxy’s starburst death. The team of astronomers were able to identify the reason for such a cataclysmic event and upon taking the data into consideration, they found it was the merger of two neighboring galaxies, which led to the creation of Galaxy ID2299.

The violent collision of the two galaxies caused a rapid dispersion of gas, which will eventually be the reason for new stars not forming in the galaxy. This is because stars are basically gas forming into spheres and burning.

When a galaxy’s stars die and no new stars are formed, that’s when a galaxy is deemed dead, which is the path Galaxy ID2299 seems to be heading. Even though the galaxy is forming stars at an alarming rate, much faster than our own Milky Way galaxy, eventually the gas will run out, as ID2299 is still ejecting gas worth ten thousand stars every year.

The lead author of the study, Annagrazia Puglisi claimed this is the first time we; humans have observed such a distant and massive star-forming galaxy, which is about to die due to its constant cold gas ejection. Even though Annagrazia Puglisi and her team were only able to observe the incident for just a few minutes, it was more than enough to spot such a tidal tail.

As for what it means to us, Emanuele Daddi, a co-author of the study, believes this will force us to rethink how we presumed a galaxy’s death would be. Theories that are well-established on the birth, death and evolution of stars might need to be revised to address this galactic merger causing such a scale of cold gas ejection.