ALBUQUERQUE, N.M. (AP) -- Scientists say they have made the most detailed
look at the center of the Milky Way galaxy and found what appears to be a
massive black hole gobbling up one star every 5,000 to 10,000 years.
   Computer-generated pictures released Wednesday at a American Astronomical
Society meeting show an object 1 million times the size of the sun that seems
to be spinning off what appears to be clusters of gas, said Northwestern
University astronomer Farhad Yusef-Zadeh.
   "This is the most detailed look at the center of our galaxy, and it is
similar, in a scaled-down version, to what we expect to see in the nuclei of
active galaxies," said Yusef-Zadeh said in a telephone interview Wednesday
night."Super-massive black holes are believed to be imbedded at the center of
these galaxies."
   A black hole is believed to be an imploded star, a massive object so dense
that even light cannot escape its gravitational pull. It is sucking in one star
every 5,000 to 10,000 years, he said. It is 25,000 light years from Earth.
   "It's an arena where gravity has a complete triumph over all other forces,"
he said of his research that involved three years of observations through the
Very Large Array radiotelescope.
   The pictures of the object, called Sagittarius A, show at least seven clumps
of gas surrounding it and seeming to spiral outward from it, as if being
sprayed out from something rapidly spinning.
   "This is the first time you can actually see bloblike sources near the
galactic center," Yusef-Zadeh said.
   Until now, he said, it had not been clear whether Sagittarius A or a star
cluster called IRS 16 was really at the center of the galaxy.
   "We believe that we have good evidence that Sagittarius A is truly at the
center of our galaxy and is responsible for energizing its immediate vicinity,"
he said.
   Although nothing can escape the interior of a black hole, Yusef-Zadeh said
that gas, dust and stars drawn toward it are believed to form a swirling disc.
The black hole's gravity, astronomers believe, heats this material to such an
extent that some of the matter is blown back outward by the radiation pressure
and by a wind similar to solar wind.
   Scientists cannot actually see the black hole but can record the energy
spewing out from it -- an amount roughly equal to the power that would be
radiated by 10 million suns. The radiotelescope can measure radio waves and
infrared radiation.
   The study was done in collaboration with astronomers Mark Morris, of
University of California, Los Angeles, and Ron Ekers of the Australian
Telescope at Epping, Australia.
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