Dark Matter

Astronomers have found evidence of the most distant water ever located in the universe, the water has been found in a another galaxy billions of light years away.

This astounding discovery was made by a joint USA - European venture and has been announced at the "European Week of Astronomy and Space Science" conference.

The water vapour is thought to be a jet stream ejected from a super-massive black hole at the centre of the distant galaxy (about 19.8 billion light years distant). The water has been observed as a "maser" which means that molecules of gas amplify and in doing so emit beams of microwave radiation.

Due to the distance and the laws of physics, the further away something is seen, the longer ago the event happened. The waters signature was seen at radio wavelengths and is only now being detected.

It has been estimated that the water that has been detected was actually emitted when the universe was only 2.5 billion years old (a fifth of its estimated current age).

John McKean of the Netherlands Institute for Radio Astronomy said:
"We have been observing the water maser every month since the detection and seen a steady signal with no apparent change in the velocity of the water vapour in the data we've obtained so far"

"This backs up our prediction that the water is found in the jet from the supermassive black hole, rather than the rotating disc of gas that surrounds it."

It is thought by some of the researchers that there were many more galaxies like this in the early universe, however surveys of nearer (and younger) galaxies has shown that only 5% have powerful water masers associated with active nuclei. Further studies have also shown that very powerful water masers are very rare when you compare them with their less luminous counterparts.

The pan-continental research group is led by Dr Violette Impellizzeri, from the Max Planck Institute for Radio Astronomy in Germany and began by using the 100m German Effelsberg radio telescope from July to September 2007.

The data was later confirmed by observations with the Expanded Very Large Array in the USA in September and October 2007.