- Ostriker-Peebles criterion
In
astronomy , the Ostriker-Peebles criterion, named after its discoverersJeremiah Ostriker andJim Peebles , describes the formation of barred galaxies.The rotating disc of a spiral galaxy, consisting of stars and solar systems, may become unstable in a way that the stars in the outer parts of the "arms" are released from the galaxy system, resulting in the collapse of the remaining stars into a bar-shaped galaxy. This occurs in approximately 1/3 of the known spiral galaxies.
Based on the first kinetic energy component "T" and the total kinetic energy "W", a galaxy will become barred when frac{T}{W} > 0.15.
External links
* [http://burro.astr.cwru.edu/Academics/Astr222/Galaxies/Spiral/bars.html About barred galaxies]
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