March 13, 2007—Imagine how the night sky might appear if you had x-ray vision, and it might look much like this—a field of black with more than a thousand glowing spots as bright and colorful as Christmas lights.

But those aren't stars; they're supermassive black holes churning away at the centers of distant galaxies.

This image, taken by a suite of space- and Earth-based telescopes, is the largest sample ever of the mysterious, light-swallowing giants, which are hundreds of millions of times more massive than the sun.

"We're trying to get a complete census across the universe of black holes and their habits," said Ryan Hickox of the Harvard-Smithsonian Center for Astrophysics (CfA), which coordinated the project, in a press statement.

"We used special tactics to hunt down the very biggest black holes."

NASA's orbiting Chandra X-Ray Observatory captured much of this panorama, which covers a swath of night sky in the constellation Bootes some 40 times larger than the full moon (inset).

The telescope made the image by detecting x-rays emitted by the black holes as they draw in material around them. These invisible rays give scientists clues as to how large, strong, and fast the objects are. (In this image, blue represents high-energy x-rays, green medium energy, and red low energy.)

This unusual group picture will give scientists plenty of material for future study into supermassive black holes, astronomers added.

"We found well over a thousand of these monsters and have started using them to test our understanding of these powerful objects," CfA's Christine Jones said.

—Blake de Pastino

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