cientists using NASA's Chandra X-ray Observatory have discovered
evidence of energetic plumes – particles that extend 300,000 light
years into a massive cluster of galaxies. The plumes are due to
explosive venting from the vicinity of a supermassive black hole, and
they provide dramatic new evidence of the influence a black hole can
have over intergalactic distances.

Image: X-ray image of Perseus Cluster. Credit: NASA/CXC/IoA/J.Sanders
et al

"In relative terms, it is as if a heat source the size of a fingernail
affects the behavior of a region the size of Earth," said Andrew
Fabian of Cambridge University, U.K. Fabian is lead author of a report
on this research that will appear in an upcoming issue of the Monthly
Notices of the Royal Astronomical Society.

Fabian's group discovered the plumes by studying data from 280 hours
(more than 1 million seconds) of Chandra observations of the Perseus
cluster, the longest X-ray observation ever taken of a galaxy cluster.
The cluster contains thousands of galaxies immersed in a vast cloud of
multi-million degree gas with the mass equivalent of trillions of
suns.

The plumes showed up in the X-ray data as low pressure regions in the
hot gas extending outward from the giant galaxy in the center of the
cluster. The low gas pressure measured in the plumes is likely the
result of the displacement of the gas by bubbles of unseen high-energy
particles.

The bubbles appear to be generated by high-speed jets blasting away
from the vicinity of the giant galaxy's supermassive black hole.
Individual bubbles seen in the inner regions expand and merge to
create vast plumes at larger distances.

"The plumes show that the black hole has been venting for at least 100
million years, and probably much longer," said co-author Jeremy
Sanders also of Cambridge University.

The venting produces sound waves which heat the gas throughout the
inner regions of the cluster and prevent the gas from cooling and
making stars at a large rate. This process has slowed the growth of
the central galaxy in the cluster, NGC 1275, which is one of the
largest galaxies in the universe.

Source: Chandra X-ray Center




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