WISE spots millions of black holes

Posted by Kate Taylor

NASA's discovered several million new black holes - along with a thousand or so galaxies obscured by dust - using the Wide-field Infrared Survey Explorer (WISE) telescope.

Images show millions of dusty black hole candidates across the universe, together with about 1,000 even dustier objects thought to be among the brightest galaxies ever found. Burning brightly with infrared light, they're nicknamed hot DOGs.

"WISE has exposed a menagerie of hidden objects," says WISE program scientist Hashima Hasan. "We've found an asteroid dancing ahead of Earth in its orbit, the coldest star-like orbs known and now, supermassive black holes and galaxies hiding behind cloaks of dust."

WISE scanned the whole sky twice in infrared light, finishing early last year, and astronomers are trawling through the results.

And they've now found about 2.5 million actively feeding supermassive black holes across the full sky, some more than 10 billion light-years away. About two-thirds of these black holes never had been detected before, as dust blocks their visible light.

Also discovered are around 1,000 of the brightest galaxies known, which can pour out more than 100 trillion times as much light as our sun, as well as churning out new stars.

"These dusty, cataclysmically forming galaxies are so rare WISE had to scan the entire sky to find them," says Peter Eisenhardt, project scientist for WISE at JPL.

"We are also seeing evidence that these record setters may have formed their black holes before the bulk of their stars. The 'eggs' may have come before the 'chickens'."

More than 100 of these objects, located about 10 billion light-years away, have now been confirmed using other telescopes. They appear to be more than twice as hot as other infrared-bright galaxies - possibly because their dust is being heated by an extremely powerful burst of activity from the supermassive black hole.

"We may be seeing a new, rare phase in the evolution of galaxies," says Jingwen Wu of JPL.