Using a giant, 100-meter-diameter radio telescope in Effelsberg, Germany and the National Science Foundation's Very Large Array (VLA) in New Mexico, scientists have found the most distant water molecules seen in the universe. “Detection at such a large distance was made possible by a closer, intervening galaxy which acted as a gravitational lens.”

From nrao.edu

“The astronomers say their discovery indicates that such giant water masers were more common in the early Universe than they are today. MG J0414+0534 is seen as it was when the Universe was roughly one-sixth of its current age.”

“At the galaxy's great distance, even the strengthening of the radio waves done by the masers would not by itself have made them strong enough to detect with the radio telescopes. However, the scientists got help from nature in the form of another galaxy, nearly 8 billion light-years away, located directly in the line of sight from MG J0414+0534 to Earth. That foreground galaxy's gravity served as a lens to further brighten the more-distant galaxy and make the emission from the water molecules visible to the radio telescopes.”

"We were only able to discover this distant water with the help of the gravitational lens," said Violette Impellizzeri, an astronomer with the Max-Planck Institute for Radioastronomy (MPIfR) in Bonn, Germany. "This cosmic telescope reduced the amount of time needed to detect the water by a factor of about 1,000," she added.”

“The astronomers first detected the water signal with the Effelsberg telescope. They then turned to the VLA's sharper imaging capability to confirm that it was indeed coming from the distant galaxy. The gravitational lens produces not one, but four images of MG J0414+0534 as seen from Earth. Using the VLA, the scientists found the specific frequency attributable to the water masers in the two brightest of the four lensed images. The other two lensed images, they said, are too faint for detecting the water signal.”

“The radio frequency emitted by the water molecules was Doppler shifted by the expansion of the Universe from 22.2 GHz to 6.1 GHz.”

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