Shooting Star Cluster
As the largest structures in the universe, clusters of galaxies make
tempting targets. Mergers, in which a galaxy or group of galaxies collide
with a larger galaxy or larger group, are fairly well known. Now for the
first time the structure of the collision has been revealed. The image
above, taken by the Chandra X-ray
observatory, clearly reveals a bow shock produced as a small set of
galaxies plows through a larger cluster. This cluster, called 1E 0657-56,
was known to be extraordinarily hot. Astronomers think that the bow shock
is the result of cool gas (here, cool mean "only" 70 million degree
Celsius) in a sub-cluster moving like a bullet (but at six million
miles per hour) plowing through hotter (100 million degree) gas in the main
part of the cluster. The gravity of the main cluster is slowing the
"bullet" sub-cluster, but astronomers think that by the time the
sub-cluster is stopped, it will have been stripped of all its gas.
Last Week *
HEA Dictionary * Archive
* Search HEAPOW
Each week the HEASARC
brings you new, exciting and beautiful images from X-ray and Gamma ray
astronomy. Check back each week and be sure to check out the HEAPOW archive!
Page Author: Dr. Michael F.
Last modified April 11, 2002