mayo 09, 2005

Creation of Black Hole Detected Today

BREAKING NEWS: Creation of Black Hole Detected Today
By Robert Roy Britt
Senior Science Writer
posted: 09 May 2005
12:52 pm ET

What happened

Steinn Sigurdsson, a Penn State University researcher who is excited about the observations but was not involved in them, explained what theorists think happened:

Over a long time period, at least a hundred million years and perhaps billions of years, the two neutron stars spiraled toward each other. Neutron stars themselves are very dense objects, collapsed stellar remnants.

"A fraction of a second before contact, the lower mass neutron star is disrupted and forms a neutrino driven accretion disk around the higher mass neutron star," Sigurdsson told "It implodes under the weight and forms a maximally spinning low-mass black hole."

Astronomers can't see black holes, because light and everything else that enters them is lost to observation. But just before material falls in, some high-energy process -- likely involving magnetism and speeds approach that of light -- vents some of the material back into space.

The gamma ray burst signals the formation of a superheated jet of gas being shot out from the chaotic region around the newly formed black hole at a significant fraction of light-speed, Sigurdsson said.

"This really does look like a merger scenario," said Gehrels, who heads up the scientific operations for the Swift satellite.

The first gamma-ray burst was detected by accident in 1967. It was found by U.S. satellites deployed to monitor possible violations of the nuclear test ban treaty. Researchers now know that one erupts roughly every day somewhere in the cosmos. Most originate many billions of light years away.

Each burst can briefly outshine an entire galaxy. Gamma-ray bursts in our own galaxy are very rare. Some scientists speculate that such bursts in the Milky Way's past might have caused mass extinctions on Earth.

Nota completa