Largest distant water reservoir in universe discovered

Astronomers have discovered what they claim is the largest and farthest reservoir of water ever detected in the universe.

Looking from a distance of 30 billion trillion miles away into a quasar, a team at California Institute of Technology has found a mass of water vapour that’s at least 140 trillion times that of all the water in the world’s oceans combined, and 100,000 times more massive than the sun.

Quasar is one of the brightest and most violent objects in the cosmos.

Because the quasar is so far away, its light has taken 12 billion years to reach Earth. The observations therefore reveal a time when the universe was just 1.6 billion years old, say the astronomers.

“The environment around this quasar is unique in that it’s producing this huge mass of water. It’s another demonstration that water is pervasive throughout the universe, even at very earliest times,” team leader Matt Bradford said.

In fact, the astronomers studied a particular quasar called APM 08279+5255, which harbours a black hole 20 billion times more massive than the sun and produces as much energy as a thousand trillion suns.

Since astronomers expected water vapour to be present even in the early universe, the discovery of water is not itself a surprise, Bradford says.

There’s water vapour in the Milky Way, although the total amount is 4,000 times less massive than in the quasar, as most of the Milky Way’s water is frozen in the form of ice, says the team.

Nevertheless, water vapour is an important trace gas that reveals the nature of the quasar. In this particular quasar, the water vapour is distributed around the black hole in a gaseous region spanning hundreds of lightyears and its presence indicates that the gas is unusually warm and dense by astronomical standards.

The findings are to be published in an upcoming issue of the Astrophysical Journal Letters.