1E 0657-56:
A Bow Shock in a Merging Galaxy Cluster
Chandra's image of the extremely
hot galaxy cluster 1E 0657-56 reveals a bow-shaped
shock wave toward the right side of the cluster.
This feature, thought to be the result of the merger of
a smaller group or sub-cluster of galaxies with 1E
0657-56, gives astronomers a rare opportunity to study
how clusters grow.
The shock wave appears to have been formed as 70
million degree Celsius gas in the sub-cluster plowed
through 100 million degree gas in the main cluster at a
speed of about 6 million miles per hour. This motion
created a wind that stripped the cooler gas from the
sub-cluster, similar to leaves from a tree being blown
off in a storm.
The speed, appearance and shape of the sub-cluster
indicates that it would have passed through the core of
the larger cluster about 150 million years ago. By the
time the gravity of the cluster stops the motion of the
sub-cluster, it is likely that the cooler gas will have
been totally stripped.
1E 0657-56 is of great interest because it is one of
the hottest known clusters. Astronomers hope to use
this and future observations to determine if the high
temperature of the cluster gas is due to shock waves
produced by the merger of many sub-clusters.
|
Fast Facts for 1E
0657-56:
|
|
Credit
|
NASA/SAO/CXC/M.Markevitch et al.
|
|
Scale
|
Image is 9 arcmin on a side.
|
|
Category
|
Groups & Clusters of Galaxies
|
|
Coordinates
(J2000)
|
RA 06h 58m 37.9s | Dec -55º 57'
0" |
|
Constellation
|
Carina
|
|
Observation
Date
|
October 16, 2000
|
|
Observation
Time
|
6.75 hours
|
|
Obs.
ID
|
554
|
|
Color
Code
|
Intensity
|
|
Instrument
|
ACIS
|
|
Distance
Estimate
|
3.8 billion light years
|
|
Release Date
|
February 20, 2002
|
|
|
