Composition
There are three main components of a galaxy cluster. They are tabulated below:
| Name of the components | Mass fraction | Description |
|---|---|---|
| Galaxies | 1% | In optical observations only galaxies are visible |
| Intergalactic gas in ICM | 9% | Plasma between the galaxies at high temperature. Emit x-ray radiation through thermal bremsstrahlung mechanism. |
| Dark matter | 90% | Most massive component, cannot be detected optically, inferred through gravitational interactions. |
Read more about this topic: Galaxy Cluster
Famous quotes containing the word composition:
“At painful times, when composition is impossible and reading is not enough, grammars and dictionaries are excellent for distraction.”
—Elizabeth Barrett Browning (1806–1861)
“Every thing in his composition was little; and he had all the weaknesses of a little mind, without any of the virtues, or even the vices, of a great one.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“Give a scientist a problem and he will probably provide a solution; historians and sociologists, by contrast, can offer only opinions. Ask a dozen chemists the composition of an organic compound such as methane, and within a short time all twelve will have come up with the same solution of CH4. Ask, however, a dozen economists or sociologists to provide policies to reduce unemployment or the level of crime and twelve widely differing opinions are likely to be offered.”
—Derek Gjertsen, British scientist, author. Science and Philosophy: Past and Present, ch. 3, Penguin (1989)