[lowenz]

Buona lettura

http://www.universetoday.com/2007/06...le-discovered/

An international team of astronomers have discovered a supermassive black hole at the very edge of the observable Universe, located 13 billion light-years away. Since the Universe is 13.7 billion years old, we're seeing this object when the Universe was only 700 million years old. Wow.

Active galactic nuclei, or quasars, occur when a supermassive black hole is feasting on infalling material. Material piles up faster than the black hole can feed, and it starts to glow so brightly that astronomers can see it clear across the Universe. This object, CFHQS J2329-0301, was discovered as part of a new distant quasar survey performed with the MegaCam imager on the Canada-France-Hawaii Telescope (CFHT).

The black hole powering the quasar is thought to have 500 million times the mass of the Sun - that makes it hungry and bright. And because the quasar is so bright, astronomers can use it as a background object to examine the gas in front. And with follow up observations, they can get more details about what kind of galaxy it formed inside.

http://sciencenow.sciencemag.org/cgi...07/607/2?rss=1

Astronomers have found what may be one of the universe's oldest supermassive black holes--an object so energetic that even medium-sized ground telescopes can still detect the radiation it emitted 13 billion years ago. The discovery suggests the need to develop "a radical alternative" to current theories of how black holes form, says astronomer Christopher Reynolds of the University of Maryland, College Park.

The new black hole--named CFHQS J2329-0301--powers a quasar, the brightest type of object in the universe, whose luminosity can vastly outshine entire galaxies. Quasars form when supermassive black holes create so much turbulence that they heat surrounding matter to temperatures of millions of degrees and then shoot it out into space at nearly the speed of light.

Discovered recently in a sky survey by an international team using the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii, the black hole at the heart of CFHQS J2329-0301 weighs more than 500 million suns. Because its distance from Earth equals its age, astronomers know that the object is 13 billion years old. What they don't know is how something so massive could have formed so early, just 700 million years after the universe was born. To have reached its observed mass so quickly, CFHQS J2329-0301 must have doubled its mass hundreds of times faster than current theory says such objects can grow, the team speculates.

"This is a problem that is occupying lots of astronomers," says team leader Chris Willott of the University of Ottawa in Canada, who with colleagues has submitted the findings to the Astronomical Journal. Some computer models explain how such massive black holes could have formed within the first billion years after the big bang, he says, such as from extra-large "seed" black holes of a few thousand solar masses, or from the collisions of whole clusters of stars. It's just that "we don't know which explanation is correct."