Distant light could be brightest yet

By Mike McNeney

Dr. Geraint Lewis

It's out there--11 billion light years out there, at the edge of the observable Universe. And it might be the brightest thing in the Universe that astronomers have ever seen.

It's an ultra-luminous quasar, discovered by UVic astronomer, Dr. Geraint Lewis and three colleagues in Europe and the U.K.

Whether the quasar is as bright as it seems--or whether its light is being magnified by other galaxies before it reaches earth--is the subject of further study.

Lewis and team are reviewing new data from radio wave measurements and this fall will have access to the Hubble Space Telescope for observations that should help pinpoint the object's brightness.

The quasar is estimated to be at least four million-billion times brighter than the Sun. It's brighter than any other observed quasar (by a factor of 10) and it outshines the brightest galaxy by more than 100 times.

"Wow," was Lewis' first reaction to the discovery. "There is a lot of matter being thrown out of this quasar at very high velocities, tens of thousands of kilometres a second. It has a lot which we feel astronomers will want to get their hands on. It will touch on several areas of extra-galactic astronomy."

Lewis and collaborators--Michael Irwin of the Royal Greenwich Observatory, Rodrigo Ibata of the European Southern Observatory in Munich and Edward Totten of Queen's University in Belfast--stumbled upon the discovery while investigating the collision between the Milky Way and the smaller Sagittarius Dwarf galaxy.

Observing cool carbon-rich stars orbiting in the halo of the Milky Way, they noticed what appeared to be a remarkably bright quasar. Suspicions were confirmed by images taken from the 2.5-meter Isaac Newton Telescope in the Canary Islands.

"It was actually a serendipitous discovery, as the best discoveries often are," said Lewis, who also conducts postdoctoral research at the University of Washington.

"The big question is, how can you feed in enough matter to generate enough energy to make this thing glow so brightly? The amount of energy that's released tells you something about how stars in galaxies like our own arose, their evolution and their history," Lewis said.

News of the discovery was featured in the esteemed British science magazine Nature (June 11 edition) and the findings have been accepted for publication in the Astrophysical Journal, the leading research journal of astronomy and astrophysics.

The discovery also caught the attention of the mainstream international news media, generating stories by CNN, BBC, the Associated Press as well as numerous Canadian and U.S. daily newspapers, TV and radio broadcasts.

The quasar--its technical name is APM08279--can be seen by amateur astronomers using a 12-inch telescope. It appears as a red blip, near the Big Dipper.

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