Live fast, die young monster galaxy discovered by astronomers

A monster galaxy that existed about 12 billion years ago has baffled scientists because of the way it lived fast and died young.

The galaxy, known as XMM-2599, formed an immense number of stars by the time the universe was only one billion-years-old.

But a mere eight million years later, it suddenly became inactive, astronomers at the University of California, Riverside, claim – and it is not clear why.

Before the universe had reached two billion years, XMM-2599 had managed to form a mass of more than 300 billion suns, postdoctoral researcher Benjamin Forrest explained in the Astrophysical Journal.


At its peak, this monster galaxy gave birth to more than 1,000 solar masses a year. By comparison, the Milky Way forms about one new star a year.

Researchers were able to make the detailed measurements and calculate the distance using powerful spectroscopic observational equipment located at the Keck Observatory on Maunakea in Hawaii.

“What makes XMM-2599 so interesting, unusual, and surprising is that it is no longer forming stars, perhaps because it stopped getting fuel or its black hole began to turn on,” said Gillian Wilson, a professor of physics and astronomy.

A question on scientists’ lips is what will become of the galaxy now its heyday is over.

“We do not know what it will turn into by the present day,” Professor Wilson continued.

“We know it cannot lose mass. An interesting question is what happens around it.

“As time goes by, could it gravitationally attract nearby star-forming galaxies and become a bright city of galaxies?”

The team behind the research have been granted additional time at the observatory to look into some of the mysteries that still remain around XMM-2599.