ASCA Science Highlights: Clusters of Galaxies
Follow the links to images and plotsOptical astronomers have discovered many clusters of galaxies, which are concentrations of galaxies near each other. X-ray astronomers have discovered that they are filled with X-ray emitting hot gas, both in and in-between the galaxies. The total mass in this hot gas exceeds that of the stars in the galaxies, and appears to be held together by an even larger amount of dark matter. The gas itself is the result of supernova explosions and tells us how the chemical elements were created in the early universe.
- ASCA data can be analyzed to generate temperature maps of clusters of galaxies. Temperature structures seen in some clusters indicate a recent merger of two clusters. Such maps may provide a good handle on how clusters are created and grow.
- The deep gravitational potential of clusters of galaxies can act as a gravitational lens. One gravitational lens was identified with a previously unrecognized, and very distant, cluster of galaxies using ASCA and ROAST data.
- The hot gas in clusters appears to have been created mostly via Type II supernovae, according to an analysis of the chemical abundances using ASCA data.
This page created by Dr. Koji Mukai (USRA) at the U.S. ASCA Guest Observer Facility.
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