Ohio University astronomer Brian McNamara and colleagues reported the
discovery of the most powerful outburst known from a supermassive black
hole. The discovery was made using NASA's earth-orbiting Chandra X-ray
Observatory. The scientists pointed the world's most powerful X-ray
telescope at a cluster of galaxies roughly 2.6 billion light-years from
Earth to study the X-rays emitted from the 60 million degree gas that
lies between the galaxies. The X-ray image revealed two enormous
cavities in the hot gas, each roughly 650,000 light years across. More
than 600 galaxies the size of our own Milky Way would fit in the
cavities. The cavities are surrounded by shock waves--sonic
booms--showing they are advancing at high speed. The cavities and sonic
booms were created by an outburst from a supermassive black hole with
the force of nearly a billion gamma-ray bursts. The black hole, whose
mass is roughly a billion times the mass of the sun, must have devoured
more than 300 million times the mass of the sun during the outburst.
This result, reported in the January 6, 2005 issue of the journal
Nature, shows that supermassive black holes shape the growth of galaxies
and large-scale structure in the Universe. Surprisingly, supermassive
black holes are growing rapidly today, and not only when the Universe
was much younger.
McNamara and his graduate student David Rafferty are members of Ohio
University's Astrophysical Institute. The work was undertaken as part of
Ohio University's 1.4 million dollar research initiative to study the
structure of the Universe on the smallest and largest scales. The
co-authors of the Nature study are Paul Nulsen (Harvard-Smithsonian
Center for Astrophysics), Michael Wise (MIT), David Rafferty (Ohio U.),
Chris Carilli (National Radio Astronomy Observatory), Craig Sarazin
(University of Virginia), and Elizabeth Blanton (Boston University).
[January 2005]
