Self-gravitation

A self-gravitating accretion disc in a quasi steady state[1]

Self-gravity is gravitational force exerted by a system, particularly a celestial body or system of bodies, onto itself. At a sufficient mass, this allows the system to hold itself together.[2] The effects of self-gravity have significance in the fields of astronomy, physics, seismology, geology, and oceanography.[3][4][5]

The strength of self-gravity differs with regard to the size of an object, and the distribution of its mass. For example, unique gravitational effects are caused by the oceans on Earth[5] or the rings of Saturn.[4] Donald Lynden-Bell, a British theoretical astrophysicist, constructed the equation[6] for calculating the conditions and effects of self gravitation. The equation's main purpose is to give exact descriptions of models for rotating flattened globular clusters. It is also used in understanding how galaxies and their accretion discs interact with each other. Outside of astronomy, self-gravity is relevant to large-scale observations (on or near the scale of planets) in other scientific fields.

  1. ^ Rice, W., Armitage, P., Bate, M. & Bonnell, I. The effect of cooling on the global stability of self-gravitating protoplanetary discs. MNRAS, 339, 1025 (2003)
  2. ^ Chamberlin, T. C. The Planetesimal Hypothesis. Journal of the Royal Astronomical Society of Canada, Vol. 10, p.473-497. November, 1916.
  3. ^ Wu, P. & van der Wal, W. Postglacial sealevels on a spherical, self-gravitating viscoelastic earth: effects of lateral viscosity variations in the upper mantle on the inference of viscosity contrasts in the lower mantle. Earth and Planetary Science Letters, Volume 211, Issues 1–2, June 15, 2003, Pages 57–68.
  4. ^ a b Colwell, J. E., Esposito, L. W. & M. Sremcevic. Self-gravity wakes in Saturn’s A ring measured by stellar occultations from Cassini. Geophysical Research Letters, volume 33, April 1, 2006. L07201 p. 1-4.
  5. ^ a b Mitrovica, J., Tamisiea, M., Davis, J. & Milne, G. Recent mass balance of polar ice sheets inferred from patterns of global sea-level change. Nature 409, p. 1026-1029. February 22, 2001.
  6. ^ Lynden-Bell, D. Stellar dynamics: Exact solution of the self-gravitation equation. Monthly Notices of the Royal Astronomical Society, Vol. 123, p.447. November, 1962.