Abell 2104:
Chandra Finds Surprising Black Hole Activity In
Galaxy Cluster
A Chandra observation of the
galaxy cluster A2104 revealed six bright X-ray sources
that are associated with supermassive black holes in
red galaxies in the cluster. Since red galaxies
are thought to be composed primarily older stars, and
to contain little gas, the observation came as a
surprise to astronomers.
Powerful X-ray emission from a supermassive black hole
comes from gas heated as it falls toward the black
hole, so an abundant supply of gas is needed to produce
the bright X-ray sources detected by Chandra.
It is generally believed that as galaxies move through
the hot cluster gas at high speeds, they are stripped
of their interstellar gas, much as a strong wind strips
leaves from a tree. Galaxies can also lose gas through
collisions with other galaxies in the cluster. The
presence of these six X-ray
sources indicates that these supermassive black
holes have somehow retained a fuel source, despite the
harsh environment of the clusters.
It could be that galaxies are better at holding onto a
supply of gas and dust than previously thought,
particularly deep down at their cores near the
supermassive black hole. Such gas and dust may explain
why the centers of the galaxies are obscured at optical
wavelengths.
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Fast Facts for Abell
2104:
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Credit
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NASA/CXC/OCIW/P.Martini et al.
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Scale
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Image is 10 arcmin on a side.
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Category
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Groups
& Clusters of Galaxies
Quasars & Active
Galaxies |
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Coordinates
(J2000)
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RA 15h 40m 07s | Dec -03º 17'
24" |
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Constellation
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Serpens
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Observation
Date
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May 25, 2000
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Observation
Time
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13.8 hours
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Obs.
ID
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895
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Color
Code
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Intensity
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Instrument
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ACIS
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Distance
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About 2 billion light years (redshift
z = 0.154)
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Release Date
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September 13, 2002
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