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View Full Version : Chandra Data Reveal Rapidly Whirling Black Holes (Forwarded)


Andrew Yee[_1_]
January 17th 08, 04:24 AM
Jennifer Morcone
Marshall Space Flight Center, Huntsville, Ala.
256-544-7199

Megan Watzke
Chandra X-ray Center, Cambridge, Mass.
617-496-7998

For Release: January 10, 2008, 2:00pm CST

Chandra Data Reveal Rapidly Whirling Black Holes

A new study using results from NASA's Chandra X-ray Observatory provides one
of the best pieces of evidence yet that many supermassive black holes are
spinning extremely rapidly. The whirling of these giant black holes drives
powerful jets that pump huge amounts of energy into their environment and
affects galaxy growth.

A team of scientists compared leading theories of jets produced by rotating
supermassive black holes with Chandra data. A sampling of nine giant
galaxies that exhibit large disturbances in their gaseous atmospheres showed
that the central black holes in these galaxies must be spinning at near
their maximum rates.

"We think these monster black holes are spinning close to the limit set by
Einstein's theory of relativity, which means that they can drag material
around them at close to the speed of light," said Rodrigo Nemmen, a visiting
graduate student at Penn State University, and lead author of a paper on the
new results presented at American Astronomical Society in Austin, Texas.

The research reinforces other, less direct methods previously used which
have indicated that some stellar and supermassive black holes are spinning
rapidly. According to Einstein's theory, a rapidly spinning black hole makes
space itself rotate. This effect, coupled with gas spiraling toward the
black hole, can produce a rotating, tightly wound vertical tower of magnetic
field that flings a large fraction of the inflowing gas away from the
vicinity of the black hole in an energetic, high-speed jet.

Computer simulations by other authors have suggested that black holes may
acquire their rapid spins when galaxies merge, and through the accretion of
gas from their surroundings.

"Extremely fast spin might be very common for large black holes," said
co-investigator Richard Bower of Durham University. "This might help us
explain the source of these incredible jets that we see stretching for
enormous distances across space."

One significant connection consequence of powerful, black-hole jets in
galaxies in the centers of galaxy clusters is that they can pump enormous
amounts of energy into their environments, and heat the gas around them.
This heating prevents the gas from cooling, and affects the rate at which
new stars form, thereby limiting the size of the central galaxy.
Understanding the details of this fundamental feedback loop between
supermassive black holes and the formation of the most massive galaxies
remains an important goal in astrophysics.

NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra
program for the agency's Science Mission Directorate. The Smithsonian
Astrophysical Observatory controls science and flight operations from the
Chandra X-ray Center in Cambridge, Mass.

Additional information and images are available at:
http://chandra.harvard.edu/photo/2008/bh_spin/
and
http://chandra.nasa.gov