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Thanks to emissions powered by monster black holes, galaxies called

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blazars rank among the most luminous objects in the universe.

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They're also the most common sources of high-energy light seen by NASA's

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Fermi Gamma-ray Space Telescope.

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Like all active galaxies, a blazar gets its energy from matter

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falling toward a central supermassive black hole.

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A small part of this material forms particle jets that travel outward in

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opposite directions at near the speed of light. What makes blazars so

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intense is that we happen to be looking almost directly down the jet.

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Now, Fermi team members have identified five

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of the most distant gamma-ray blazars known.

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The record holder emitted its light when the universe was just one-tenth its current age.

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That object hosts a black hole with a mass of about

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3 billion suns. That's 750 times bigger than

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the black hole at the heart of our own galaxy. Another of these distant

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blazars boasts a black hole more than twice this size.

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In fact, the observed properties of all five of these blazars

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show they're the most extreme known members of this extreme

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galaxy class. The discovery makes it clear that

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enormous black holes formed very early in cosmic history,

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but astronomers aren't sure how. In general it's thought that

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large galaxies--and their black holes--were built up over time through a

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series of mergers with other smaller galaxies.

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It is unknown exactly how mergers can build a

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billion-solar-mass black hole before the universe is much more than

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one billion years old. But after netting five of these extreme blazars,

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researchers hope to find more of them in Fermi data.

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These objects allow scientists to map out how the most powerful jets in the universe

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evolved over cosmic time scales. And scientists hope

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that additional examples will help them better understand

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how supermassive black holes developed so rapidly in the early universe.

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