| The
image shows a colossal cosmic "weather system" produced by the
collision of two giant clusters of galaxies. For the first time, the pressure
fronts in the system can be traced in detail, and they show a bright, but
relatively cool 50 million degree central region (white) embedded in large
elongated cloud of 70 million degree gas (magenta), all of which is roiling
in a faint atmosphere of 100 million degree gas (faint magenta and dark
blue). The bright source in the upper left is an active galaxy in the cluster. |
 |
Abell
2142 is six million light years across and contains hundreds of galaxies
and enough gas to make a thousand more. It is one of the most massive objects
in the universe. Galaxy clusters grow to vast sizes as smaller clusters
are pulled inward under the influence of gravity. They collide and merge
over the course of billions of years, releasing tremendous amounts of energy
that heats the cluster gas. The smoothness of the elongated cloud in the
Chandra image suggests that these sub-clusters have collided two or three
times in a billion years or more, and have nearly completed their merger. |
|
