A2142 - Optical Image
The two large elliptical galaxies indicated by arrows in the center of image are aligned in the general direction of the X-ray brightness elongation. They are thought to be the central galaxies of two sub-clusters that are participating in the merger.
(Credit: Palomar Digitized Sky Survey)

A2142 - Optical Image with X-ray contours
The two large elliptical galaxies indicated by arrows in the center of image are aligned in the general direction of the X-ray brightness elongation. They are thought to be the central galaxies of two sub-clusters that are participating in the merger. The optical image is overlaid with X-ray brightness contours.
(Credit: Palomar Digitzed Sky Survey and NASA/CXC/SAO)

Chandra X-ray Image with Scale Bar
Scale bar = 1 arcmin
(Credit: NASA/CXC/SAO)

Rosat Image of A2142
This image of A2142 was made the German Roentgensatellite (Rosat) X-ray observatory using the Position Sensitive Proportional Counter. It shows the entire cluster. The image is 30 arcminutes on a side.
(Credit: Rosat/J.P. Henry & U. Briel)