Abell 2256, in a "true color" radio image made with the VLA
Credit: Owen et al., NRAO/AUI/NSF
Researchers using the Karl G. Jansky Very Large Array (VLA) have
produced the most detailed image yet of a fascinating region where
clusters of hundreds of galaxies are colliding, creating a rich variety
of mysterious phenomena visible only to radio telescopes.
The
scientists took advantage of new VLA capabilities to make a "true color"
radio image. This image shows the region as it would appear if human
eyes were sensitive to radio waves instead of light waves. In this
image, red shows where longer radio waves predominate, and blue shows
where shorter radio waves predominate, following the pattern we see in
visible light.
The image shows a number of strange features the
astronomers think are related to an ongoing collision of galaxy
clusters. The region is called Abell 2256, and is about 800 million
light-years from Earth and some 4 million light-years across. The image
covers an area in the sky almost as large as the full moon. Studied by
astronomers for more than half a century with telescopes ranging from
radio to X-ray, Abell 2256 contains a fascinating variety of objects,
many of whose exact origins remain unclear.
With monikers such as
"Large Relic," "Halo," and "Long Tail," the features in this region are
seen in greater fidelity than ever before, said Frazer Owen, of the
National Radio Astronomy Observatory (NRAO). "The image reveals details
of the interactions between the two merging clusters and suggests that
previously unexpected physical processes are at work in such
encounters," he said.
Owen worked with Lawrence Rudnick of the
University of Minnesota; Jean Eilek of New Mexico Tech; and Urvashi Rau,
Sanjay Bhatnagar, and Leonid Kogan of NRAO. The researchers presented
their results in the Astrophysical Journal.
The National
Radio Astronomy Observatory is a facility of the National Science
Foundation, operated under cooperative agreement by Associated
Universities, Inc.
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Contact:
Dave Finley, Public Information Officer
(575) 835-7302
dfinley@nrao.edu
