"Bully" black hole blasts nearby galaxy: NASA
By Maggie Fox, Health and Science Editor
Tue Dec 18, 2007 6:03am EST
WASHINGTON (Reuters) - A "death star" galaxy is sending out a powerful jet of
particles and magnetic radiation that is likely obliterating any possible life
in its broad path, notably in a nearby galaxy, astronomers said on
Monday.
They said the two galaxies appear to be merging and the disturbance in the
magnetic field caused by this movement may have awakened a dormant, supermassive
black hole in one of the galaxies.
They have images of the deadly blast, spurting out from a system known as
3C321.
Data from NASA's Chandra X-ray Observatory show both galaxies have
supermassive black holes at their centers, and 3C321, the larger galaxy, is
emitting this stream of energy and particles. The unnamed smaller galaxy
apparently has swung into the path of this jet.
The astronomers agree that both galaxies are likely to have planetary systems
but nothing resembling life on any planet could survive the blast. While such
jets have been seen before, this is the first time one has been observed
battering another galaxy, the researchers report in The Astrophysical
Journal.
"First its enormous gamma ray radiation field is likely to destroy the ozone
layer," Dan Evans of the Harvard-Smithsonian Center for Astrophysics, who led
the study, told reporters in a telephone briefing.
And the magnetic field of any planet would be compressed, leaving it
vulnerable to solar storms from its star.
"There are tens to hundreds of millions of stars in the path. Some of those
stars almost certainly have planets," said Martin Hardcastle an astrophysicist
at Britain's University of Hertfordshire.
"It's ... like a bully, a black hole bully, punching the nose of any passing
galaxy," Neil deGrasse Tyson, director of the Hayden Planetarium at the American
Museum of Natural History in New York, told the briefing.
There is no need to worry about this death ray hitting Earth -- the galaxies
are 1.4 billion light years away -- a light year being the distance light
travels in a year, or about 6 trillion miles.
Several telescopes were used to build a picture of the violent event,
including the Chandra observatory, Hubble Space Telescope, and Spitzer Space
Telescope, as well as Earthbound observatories such as the Very Large Array
telescope in New Mexico and Britain's Multi-Element Radio Linked Interferometer
Network or MERLIN telescopes.
Such jets from black holes have been seen before, and they produce high
amounts of radiation, especially high-energy X-rays and gamma-rays.
"In addition to that, there is high energy radiation coming out from the
center of the active galaxy. That is not the jet," Evans said.
It is not clear why the larger galaxy started shooting out these deadly rays.
"We know how you can trigger a black hole by having two galaxies interact
because it disrupts the gravity field that was previously stable," Tyson
said.
Evans said the two galaxies appear to be in the process of a
billion-year-long-merger. "They are actually doing somewhat of a dance around
each other," he said.
It may not mean all death and destruction -- such events can eventually lead
to the creation of "stellar nurseries" and the birth of new stars, Tyson
said.
(Editing by Philip Barbara)
Original article: Reuters
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