Sunday, March 21, 2010

"Immaculate" Black Holes Found at Universe's Conception

photo;young;black;hole;quasar
A newfound black hole sits in the middle of a young, star-rich galaxy in an artist's rendering.

Illustration by ASA/JPL-Caltech


A newfound pair of ancient, supermassive black holes may lift the veil on how stars and galaxies form, a new study says.

That's because the black holes, which belong to a special group known as quasars, are what astronomers are calling the first "immaculate"—and thus unobscured by dust clouds—quasars ever found.

Quasars lie at the hearts of galaxies, and are thousands to millions of times more massive than stellar black holes, which are created when huge stars die. (See black hole pictures.)

Quasars also emit enormous amounts of light, making them detectable even from the very edge of the observable universe. Because it takes billions of years for light to reach us from the edge of the visible universe, the data we receive from these regions actually allows scientists to look back in time.

(Related: "First Triple Quasar Found, May Shed Light on Early Universe.")

But most quasars—which were "conceived" less than a billion years after the big bang—are also surrounded by doughnut-shaped clouds of dust and gas that make observations difficult, said study co-author Dean Hines, an astronomer at the Space Science Institute in Boulder, Colorado.

Immaculate Black Holes Confirm Theories

Scientists had predicted the existence of quasars J0005-0006 and J0303-0019, but the black holes were spotted only recently by NASA's infrared Spitzer Space Telescope.

According to galatic-evolution theories, the youngest and most primitive quasars should be dust free, because the stars in their galaxies haven't had time to grow old yet, Hines said. The primordial universe also wouldn't have contained the molecules necessary to form dust.

Indeed, the Spitzer telescope registers quasar dust clouds as unique infrared signals—conspicuously missing from the newly discovered black holes.

"The fact that these two quasars don't have dust means our theories aren't broken," Hines said.

"If it turned out that all the quasars found at the beginning of the universe were dusty, that would be hard to explain."

Research appears March 18 in the journal Nature.

via "Immaculate" Black Holes Found at Universe's Conception.

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